Takahashi is a user of a site that hosts programming contests.

When a user competes in a contest, the rating of the user (not necessarily an integer) changes according to the performance of the user, as follows:  
 - Let the current rating of the user be a.
 - Suppose that the performance of the user in the contest is b.
 - Then, the new rating of the user will be the avarage of a and b.
For example, if a user with rating 1 competes in a contest and gives performance 1000, his/her new rating will be 500.5, the average of 1 and 1000.
Takahashi's current rating is R, and he wants his rating to be exactly G after the next contest.

Find the performance required to achieve it.  

-----Constraints-----
 - 0 \leq R, G \leq 4500
 - All input values are integers.

-----Input-----
Input is given from Standard Input in the following format:
R
G

-----Output-----
Print the performance required to achieve the objective.

-----Sample Input-----
2002
2017

-----Sample Output-----
2032

Takahashi's current rating is 2002.

If his performance in the contest is 2032, his rating will be the average of 2002 and 2032, which is equal to the desired rating, 2017.
[{"code": "# \u73fe\u5728\u3068\u76ee\u6a19\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u53d6\u5f97\nR = int(input())\nG = int(input())\n\n# \u76ee\u6a19\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u306b\u306a\u308b\u305f\u3081\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u6570\u5024\u3092\u8a08\u7b97\nTarget = (G * 2) - R\n\n# \u8a08\u7b97\u7d50\u679c\u3092\u51fa\u529b\nprint(Target)", "passed": true, "time": 0.34, "memory": 14284.0, "status": "done"}, {"code": "R=int(input())\nG=int(input())\nprint((2*G-R))\n", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint(2*G-R)", "passed": true, "time": 0.15, "memory": 13988.0, "status": "done"}, {"code": "# \u9ad8\u6a4b\u541b\u306f\u3042\u308b\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u30b3\u30f3\u30c6\u30b9\u30c8\u304c\u884c\u308f\u308c\u3066\u3044\u308b\u30b5\u30a4\u30c8\u306b\u53c2\u52a0\u3057\u3066\u3044\u307e\u3059\u3002\n# \u3053\u3053\u3067\u306f, \u30b3\u30f3\u30c6\u30b9\u30c8\u306b\u51fa\u5834\u3057\u305f\u6642\u306b\u3053\u306e\u9806\u4f4d\u306b\u5fdc\u3058\u3066\u300c\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u300d\u3068\u3044\u3046\u3082\u306e\u304c\u3064\u304d\u3001\n# \u305d\u308c\u306b\u3088\u3063\u3066\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0 (\u6574\u6570\u3068\u306f\u9650\u3089\u306a\u3044) \u304c\u6b21\u306e\u3088\u3046\u306b\u5909\u5316\u3057\u307e\u3059\u3002\n#\n# \u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092 a \u3068\u3059\u308b\u3002\n# \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067, \u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9 b\u3092\u53d6\u3063\u305f\u3068\u3059\u308b\u3002\n# \u305d\u306e\u3068\u304d, \u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u306f a \u3068 b \u306e\u5e73\u5747\u307e\u3067\u5909\u5316\u3059\u308b\u3002\n# \u4f8b\u3048\u3070, \u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u304c 1 \u306e\u4eba\u304c\n# \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9 1000\u3092\u53d6\u3063\u305f\u3089,\n# \u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u306f 1 \u3068 1000 \u306e\u5e73\u5747\u3067\u3042\u308b 500.5 \u306b\u306a\u308a\u307e\u3059\u3002\n#\n# \u9ad8\u6a4b\u541b\u306f, \u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u304c R \u3067,\n# \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u3061\u3087\u3046\u3069 G\u306b\u3057\u305f\u3044\u3068\u601d\u3063\u3066\u3044\u307e\u3059\u3002\n# \u305d\u306e\u3068\u304d, \u9ad8\u6a4b\u541b\u304c\u53d6\u308b\u3079\u304d\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u6c42\u3081\u306a\u3055\u3044\u3002\n\n# \u5236\u7d04\n# 0 \u2266 R, G \u2266 4500\n# \u5165\u529b\u306f\u3059\u3079\u3066\u6574\u6570\n\n# \u6a19\u6e96\u5165\u529b\u304b\u3089 R, G \u306e\u5024\u3092\u53d6\u5f97\u3059\u308b\nr = int(input())\ng = int(input())\n\n# \u9ad8\u6a4b\u541b\u304c\u53d6\u308a\u3079\u304d\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u8a08\u7b97\u3057\u3001\u51fa\u529b\u3059\u308b\n# (r + x) / 2 = G\nresult = g * 2  - r\n\nprint(result)\n", "passed": true, "time": 0.23, "memory": 14156.0, "status": "done"}, {"code": "def iroha():\n    a = [int(input()) for _ in range(2)]\n    print((2*a[1]-a[0]))\n    \n\ndef __starting_point():\n    iroha()\n\n\n__starting_point()", "passed": true, "time": 0.14, "memory": 14088.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(2*G-R)", "passed": true, "time": 0.14, "memory": 14028.0, "status": "done"}, {"code": "a=int(input())\nb= int(input())\nprint(b*2-a)", "passed": true, "time": 0.14, "memory": 14220.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(G * 2 - R)", "passed": true, "time": 0.15, "memory": 14260.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(G * 2 - R)", "passed": true, "time": 0.38, "memory": 14204.0, "status": "done"}, {"code": "# \u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u304c R \u3067, \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u3061\u3087\u3046\u3069 G \u306b\u3057\u305f\u3044\n# \u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u306f\u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3068\u6b21\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u5e73\u5747\n\nR = int(input())\nG = int(input())\n\nb = 2*G - R\nprint(b)\n", "passed": true, "time": 0.5, "memory": 14156.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint((2 * G - R))\n\n# \u9ad8\u6a4b\u541b\u304c\u53d6\u308b\u3079\u304d\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092X\u3068\u7f6e\u304f\u3068\u3000(R + X) / 2 = G \u3068\u306a\u308b\u3002\n# \u5f0f\u3092\u5909\u5f62\u3059\u308b\u3068\u3000X = 2 * G - R \u3068\u306a\u308b\u3002\u3053\u308c\u304c\u9ad8\u6a4b\u541b\u304c\u53d6\u308b\u3079\u304d\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3002\n", "passed": true, "time": 0.14, "memory": 14060.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nx = 2 * g - r\n\nprint(x)", "passed": true, "time": 0.14, "memory": 14252.0, "status": "done"}, {"code": "x=int(input())\ny=int(input())\nprint(y+(y-x))", "passed": true, "time": 0.33, "memory": 14188.0, "status": "done"}, {"code": "current_rating = int(input())\nfinal_rating = int(input())\nperformance = final_rating * 2 - current_rating\nprint(performance)", "passed": true, "time": 0.14, "memory": 14284.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(2* G - R)", "passed": true, "time": 0.14, "memory": 14248.0, "status": "done"}, {"code": "print((-1) * int(input()) + 2 * int(input()))", "passed": true, "time": 0.22, "memory": 14212.0, "status": "done"}, {"code": "import bisect,collections,copy,heapq,itertools,math,string\nimport sys\ndef I():\n    #1 line 1 int\n     return int(sys.stdin.readline().rstrip())\ndef LI():\n    #1 line n int\n     return list(map(int,sys.stdin.readline().rstrip().split()))\ndef S():\n    #1 line 1 string\n     return sys.stdin.readline().rstrip()\ndef LS():\n    #1 line n strings\n     return list(sys.stdin.readline().rstrip().split())\n\nR=I()\nG=I()\n\nx=2*G-R\nprint(x)", "passed": true, "time": 0.15, "memory": 14332.0, "status": "done"}, {"code": "a=int(input())\nb=int(input())\nprint(2*b-a)", "passed": true, "time": 0.14, "memory": 14220.0, "status": "done"}, {"code": "a = int(input())\nb = int(input())\n\nprint(2*b-a)", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "R, G = (int(input()) for i in range(2))\nprint(G * 2 - R)", "passed": true, "time": 0.14, "memory": 14172.0, "status": "done"}, {"code": "# \u5165\u529b\nR = int(input())\nG = int(input())\n\n# \u51fa\u529b\n\nif 0 <= R and G <= 4500:\n    print(G * 2 - R)", "passed": true, "time": 0.14, "memory": 14080.0, "status": "done"}, {"code": "r = int(input())\nn = int(input())\nprint((n * 2 - r))\n", "passed": true, "time": 0.15, "memory": 14300.0, "status": "done"}, {"code": "print(-int(input()) + 2 * int(input()))", "passed": true, "time": 0.14, "memory": 14008.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint((G+(G-R)))\n", "passed": true, "time": 0.14, "memory": 14248.0, "status": "done"}, {"code": "# \u5165\u529b\nr = int(input())\ng = int(input())\n\n# \u51e6\u7406\nanswer = 2 * g - r\n\nprint(answer)\n\n", "passed": true, "time": 0.14, "memory": 14064.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint(2 * G - R)", "passed": true, "time": 0.14, "memory": 14248.0, "status": "done"}, {"code": "# A - Rating Goal\n\n# \u73fe\u5728\u306e\u30ec\u30fc\u30c8\u3092a, \u30b3\u30f3\u30c6\u30b9\u30c8\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092b\u3068\u3059\u308b\u3068\u3001\u30ec\u30fc\u30c8\u306fa\u3068b\u306e\u5e73\u5747\u307e\u3067\u5909\u5316\u3059\u308b\n# \u73fe\u5728\u306e\u30ec\u30fc\u30c8\u3092R, \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067\u306e\u76ee\u6a19\u30ec\u30fc\u30c8\u3092G\u3068\u3057\u305f\u5834\u5408\u3001\u53d6\u308b\u3079\u304d\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u51fa\u529b\u3059\u308b\n\n\nR = int(input())\nG = int(input())\n\nprint(((G * 2) - R))\n", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nprint(2*g-r)", "passed": true, "time": 0.14, "memory": 14192.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(2*g-r)", "passed": true, "time": 0.15, "memory": 14264.0, "status": "done"}, {"code": "a = int(input())\nb = int(input())\nprint(b + (b - a))", "passed": true, "time": 0.14, "memory": 14036.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(2 * G - R)", "passed": true, "time": 0.36, "memory": 14024.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nans = g * 2 - r\n\nprint(ans)", "passed": true, "time": 0.14, "memory": 14204.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(g*2-r)", "passed": true, "time": 0.14, "memory": 14300.0, "status": "done"}, {"code": "R=int(input())\nG=int(input())\nprint(G*2-R)", "passed": true, "time": 0.5, "memory": 14204.0, "status": "done"}, {"code": "R = int(input())  # \u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\nG = int(input())  # \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067\u3068\u308a\u305f\u3044\u3068\u601d\u3063\u3066\u308b\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\n\n# \u9ad8\u6a4b\u541b\u304c\u53d6\u308b\u3079\u304d\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u51fa\u529b\nprint(G*2 - R)", "passed": true, "time": 0.15, "memory": 14060.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(2 * g - r)", "passed": true, "time": 0.14, "memory": 14084.0, "status": "done"}, {"code": "S_list = [int(input()) for i in range(2)]\n\nmokuhyou = 2 * S_list[1] - S_list[0]\nprint(mokuhyou)\n", "passed": true, "time": 0.14, "memory": 14260.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint((2 * G - R))\n", "passed": true, "time": 0.14, "memory": 14192.0, "status": "done"}, {"code": "R=int(input())\nG=int(input())\nprint(G*2-R)", "passed": true, "time": 0.14, "memory": 14088.0, "status": "done"}, {"code": "a=int(input())\nb=int(input())\nprint(2*b-a)", "passed": true, "time": 0.14, "memory": 13980.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nprint(2*g-r)", "passed": true, "time": 0.23, "memory": 14204.0, "status": "done"}, {"code": "print((-int(input()) + int(input()) * 2))\n", "passed": true, "time": 0.14, "memory": 14200.0, "status": "done"}, {"code": "a,b=[int(input()) for i in range(2)]\n\nprint(2*b-a)", "passed": true, "time": 0.14, "memory": 14168.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(2*g - r)", "passed": true, "time": 0.14, "memory": 14204.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\ng = g * 2\nprint(g-r)", "passed": true, "time": 0.15, "memory": 14048.0, "status": "done"}, {"code": "R=int(input())\nG=int(input())\nprint(2*G-R)", "passed": true, "time": 0.2, "memory": 14192.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(2 * G - R)", "passed": true, "time": 0.14, "memory": 14160.0, "status": "done"}, {"code": "R, G = (int(input()) for i in range(2))\n\nR += (G - R) * 2\n\nprint(R)", "passed": true, "time": 0.17, "memory": 14196.0, "status": "done"}, {"code": "r=int(input())\ng=int(input())\nprint(2*g-r)", "passed": true, "time": 0.24, "memory": 14064.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint((g * 2 - r))\n", "passed": true, "time": 0.14, "memory": 14248.0, "status": "done"}, {"code": "#76\nr=int(input())\ng=int(input())\nprint(2*g-r)", "passed": true, "time": 0.14, "memory": 14184.0, "status": "done"}, {"code": "a=int(input())\nb=int(input())\nprint(2*b-a)", "passed": true, "time": 0.24, "memory": 14268.0, "status": "done"}, {"code": "# 076_a\nR=int(input())\nG=int(input())\nif (0<=R and R<=4500) and (0<=G and G<=4500):\n    print((2*G-R))\n", "passed": true, "time": 0.16, "memory": 14204.0, "status": "done"}, {"code": "r=int(input())\ng=int(input())\nans=2*g-r\nprint(ans)", "passed": true, "time": 0.14, "memory": 14224.0, "status": "done"}, {"code": "# \u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092 a \u3068\u3059\u308b\u3002\n# \u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u3067, \u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9 b \u3092\u53d6\u3063\u305f\u3068\u3059\u308b\u3002\n#\u305d\u306e\u3068\u304d, \u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u306f a \u3068 b \u306e\u5e73\u5747\u307e\u3067\u5909\u5316\u3059\u308b\u3002\n\n# \u73fe\u5728\u306e\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0 R \u3068\u3000\u76ee\u6307\u3057\u305f\u3044\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0 G \u3092\u5165\u529b\nR = int(input())\nG = int(input())\n# print(R, G)\n\n# \u3068\u308b\u3079\u304d\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9 \u3092 x \u3068\u3059\u308b\u3068\u3001\n# \u76ee\u6307\u3057\u305f\u3044\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3000G = (R+x)/2\u3000\n# \u4ee5\u4e0b\u5f0f\u5909\u63db\n# 2G = R + x\n# x = 2G - R\n\nx = (2 * G) - R\n# print(x)\n\n# \u7b54\u3048\u3092\u4ee3\u5165\nanswer = x\nprint(answer)\n", "passed": true, "time": 0.14, "memory": 14188.0, "status": "done"}, {"code": "a=int(input())\nb=int(input())\nprint(b*2-a)", "passed": true, "time": 0.14, "memory": 14192.0, "status": "done"}, {"code": "def main():\n  my_rate = int(input())\n  avarage_rate = int(input())\n  \n  target_rate = (avarage_rate * 2) - my_rate\n  \n  print(target_rate)\n\ndef __starting_point():\n  main()\n__starting_point()", "passed": true, "time": 0.23, "memory": 14244.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nans = 2*G - R\nprint(ans)", "passed": true, "time": 0.14, "memory": 14196.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nprint((int(2 * g - r)))\n", "passed": true, "time": 0.14, "memory": 14268.0, "status": "done"}, {"code": "print(-int(input()) + int(input()) * 2)", "passed": true, "time": 0.14, "memory": 14036.0, "status": "done"}, {"code": "print(-int(input())+int(input())*2)", "passed": true, "time": 0.22, "memory": 14048.0, "status": "done"}, {"code": "r=int(input())\ng=int(input())\nprint(2*g-r)", "passed": true, "time": 0.15, "memory": 14248.0, "status": "done"}, {"code": "# A - Rating Goal\n# https://atcoder.jp/contests/abc076/tasks/abc076_a\n\nR = int(input())\nG = int(input())\n\nprint((G * 2 - R))\n", "passed": true, "time": 0.14, "memory": 14088.0, "status": "done"}, {"code": "r=int(input())\ng=int(input())\nprint(2*g-r)", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "r=int(input())\nc=int(input())\nprint(2*c-r)", "passed": true, "time": 0.15, "memory": 14060.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint((2 * g - r))\n", "passed": true, "time": 0.14, "memory": 14216.0, "status": "done"}, {"code": "r=int(input())\ng=int(input())\nprint(g*2-r)", "passed": true, "time": 0.15, "memory": 14068.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(G * 2 - R)", "passed": true, "time": 0.14, "memory": 14188.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nprint(2*g - r)", "passed": true, "time": 0.14, "memory": 14280.0, "status": "done"}, {"code": "def main():\n    r = int(input())\n    g = int(input())\n\n    x = 2 * g - r\n    print(x)\n    \n    \nmain()", "passed": true, "time": 0.14, "memory": 14220.0, "status": "done"}, {"code": "a=int(input())\nb=int(input())\n\nprint((a+(b-a)*2))\n", "passed": true, "time": 0.23, "memory": 14312.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(G*2-R)", "passed": true, "time": 0.14, "memory": 14284.0, "status": "done"}, {"code": "print(-int(input()) + 2*int(input()))", "passed": true, "time": 0.14, "memory": 14028.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint((G * 2 - R))\n", "passed": true, "time": 0.14, "memory": 14088.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\n# (answer + R)/ 2 = G\n\nanswer = 2 * G -R\nprint(answer)", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint((2 * G) - R)", "passed": true, "time": 0.14, "memory": 14184.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nrating = G * 2 - R\nprint(rating)", "passed": true, "time": 0.24, "memory": 14272.0, "status": "done"}, {"code": "# 076a\n\nR = int(input())\nG = int(input())\n\nB = G * 2 - R\nprint(B)\n", "passed": true, "time": 0.14, "memory": 14164.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(2*g-r)", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(2*G-R)", "passed": true, "time": 0.15, "memory": 14160.0, "status": "done"}, {"code": "r=int(input())\ng=int(input())\nans=(g*2)-r\nprint((int(ans)))\n", "passed": true, "time": 0.14, "memory": 14208.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint(2*G - R)", "passed": true, "time": 0.15, "memory": 14056.0, "status": "done"}, {"code": "import bisect, collections, copy, heapq, itertools, math, string, sys\ninput = lambda: sys.stdin.readline().rstrip() \nsys.setrecursionlimit(10**7)\nINF = float('inf')\ndef I(): return int(input())\ndef F(): return float(input())\ndef SS(): return input()\ndef LI(): return [int(x) for x in input().split()]\ndef LI_(): return [int(x)-1 for x in input().split()]\ndef LF(): return [float(x) for x in input().split()]\ndef LSS(): return input().split()\n\ndef resolve():\n    R = I()\n    G = I()\n\n    ans = 2 * G - R\n    print(ans)\n\ndef __starting_point():\n    resolve()\n\n__starting_point()", "passed": true, "time": 0.14, "memory": 14096.0, "status": "done"}, {"code": "#   AtCoder abc076 a\n#   \u30b9\u30c8\u30ec\u30c3\u30c1\u8ab2\u984c\n\n#   \u5165\u529b\n#   \u30df\u30b9\u3000r, g = map(int, input().split())\nr = int(input())\ng = int(input())\n\n#   \u51e6\u7406\n#   G = (R + answer) / 2 -> answer = 2G - R\nanswer = 2 * g - r\n\n#   \u51fa\u529b\nprint(answer)\n", "passed": true, "time": 0.25, "memory": 14064.0, "status": "done"}, {"code": "# \u73fe\u5728\u306e\u30ec\u30fc\u30c8R\u3068\u30b3\u30f3\u30c6\u30b9\u30c8\u5f8c\u306e\u76ee\u6307\u3057\u305f\u3044\u30ec\u30fc\u30c8G\u3092\u5165\u529b\nR = int(input())\nG = int(input())\n# G\u306e2\u500d\u304b\u3089\u73fe\u5728\u306e\u30ec\u30fc\u30c8R\u3092\u5f15\u3044\u3066\u3001\u6b21\u306e\u30b3\u30f3\u30c6\u30b9\u30c8\u306e\u30ec\u30fc\u30c8\u3092\u51fa\u529b\nprint(G * 2 - R)", "passed": true, "time": 0.14, "memory": 14300.0, "status": "done"}, {"code": "#!/usr/bin/env python3\nimport sys\nsys.setrecursionlimit(10**6)\n\nr = int(input())\ng = int(input())\n\nprint((2*g-r))\n", "passed": true, "time": 0.14, "memory": 14056.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint((G + (G - R)))\n", "passed": true, "time": 0.14, "memory": 14072.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\nprint(G * 2 - R)", "passed": true, "time": 0.22, "memory": 14160.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(r+2*(g-r))", "passed": true, "time": 0.23, "memory": 14264.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(2*g-r)", "passed": true, "time": 0.14, "memory": 14060.0, "status": "done"}, {"code": "# \u5165\u529b\nR = int(input())\nG = int(input())\n\n# \u51e6\u7406\nanswer = 2 * G - R\n\n# \u51fa\u529b\nprint(answer)", "passed": true, "time": 0.14, "memory": 14276.0, "status": "done"}, {"code": "R = int(input())\nG = int(input())\n\nprint(2 * G - R)", "passed": true, "time": 0.15, "memory": 14272.0, "status": "done"}, {"code": "# \u5165\u529b\nR = int(input())\nG = int(input())\n\n# (R+G)/2=X X=2G-R\nperformance = G * 2 - R\n\n# \u51fa\u529b\nprint(performance)", "passed": true, "time": 0.15, "memory": 14308.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\n\nprint(2 * g - r)", "passed": true, "time": 0.14, "memory": 14276.0, "status": "done"}, {"code": "a=int(input())\nb=int(input())\nprint(a+(b-a)*2)", "passed": true, "time": 0.15, "memory": 14068.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nperformance = 2 * g - r\nprint(performance)", "passed": true, "time": 0.14, "memory": 14028.0, "status": "done"}, {"code": "r,g=int(input()),int(input())\nprint(2*g-r)", "passed": true, "time": 0.14, "memory": 14028.0, "status": "done"}, {"code": "r = int(input())\ng = int(input())\nprint(g*2 - r)", "passed": true, "time": 0.14, "memory": 14160.0, "status": "done"}, {"code": "R=int(input())\nG=int(input())\nprint((G*2-R))\n", "passed": true, "time": 0.13, "memory": 14160.0, "status": "done"}]