Snuke has a grid consisting of three squares numbered 1, 2 and 3.
In each square, either 0 or 1 is written. The number written in Square i is s_i.
Snuke will place a marble on each square that says 1.
Find the number of squares on which Snuke will place a marble.

-----Constraints-----
 - Each of s_1, s_2 and s_3 is either 1 or 0.

-----Input-----
Input is given from Standard Input in the following format:
s_{1}s_{2}s_{3}

-----Output-----
Print the answer.

-----Sample Input-----
101

-----Sample Output-----
2

 - A marble will be placed on Square 1 and 3.
[{"code": "s=input()\ncount=0\nfor i in range(len(s)):\n    if(s[i]==\"1\"):\n        count+=1\nprint(count)", "passed": true, "time": 1.86, "memory": 14280.0, "status": "done"}, {"code": "a=input()\nprint((a.count('1')))\n", "passed": true, "time": 0.15, "memory": 14244.0, "status": "done"}, {"code": "# -*- coding: utf-8 -*-\n# \u6574\u6570\u306e\u5165\u529b\ns = input()\nnumber = \"1\"\n\ncount = s.count(number)\nprint(count)", "passed": true, "time": 0.33, "memory": 14052.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.31, "memory": 14272.0, "status": "done"}, {"code": "cnt = 0\nfor s in input():\n  if int(s) == 1:\n    cnt += 1\nprint(cnt)", "passed": true, "time": 0.14, "memory": 14284.0, "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\nx=S()\ncount=0\nfor s in x:\n    if s == \"1\":\n        count += 1\n        \nprint(count)", "passed": true, "time": 1.95, "memory": 14268.0, "status": "done"}, {"code": "s = input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.15, "memory": 14292.0, "status": "done"}, {"code": "s = list(input())\ncount = 0\nfor i in range(0, len(s)):\n    if s[i] == \"1\":\n        count += 1\n\nprint(count)", "passed": true, "time": 0.14, "memory": 14076.0, "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 ints\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\nx = S()\n\ncount = 0\nfor s in x:\n    if s == \"1\":\n        count += 1\n\nprint(count)", "passed": true, "time": 0.32, "memory": 14248.0, "status": "done"}, {"code": "s=input()\nprint(s.count('1'))", "passed": true, "time": 1.89, "memory": 14056.0, "status": "done"}, {"code": "s = list(map(int, input()))\ncount = 0\nfor i in range(len(s)):\n  if s[i] == 1:\n    count +=1\nprint(count)", "passed": true, "time": 0.14, "memory": 14300.0, "status": "done"}, {"code": "a = input()\ncount = 0\nfor i in a:\n    if i == '1':\n        count += 1\n    else:\n        pass\nprint(count)\n", "passed": true, "time": 0.17, "memory": 14300.0, "status": "done"}, {"code": "print(sum([int(ss) for ss in input()]))", "passed": true, "time": 0.14, "memory": 14228.0, "status": "done"}, {"code": "s1,s2,s3 = list(map(str, input()))\ncounter = 0\nif s1 == \"1\":\n    counter += 1\nif s2 == \"1\":\n    counter += 1\nif s3 == \"1\":\n    counter += 1\nprint(counter)\n", "passed": true, "time": 0.23, "memory": 14196.0, "status": "done"}, {"code": "m = 0\nfor s in list(input()):\n    if int(s) == 1:\n        m += 1\nprint(m)\n", "passed": true, "time": 0.14, "memory": 14160.0, "status": "done"}, {"code": "s=input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14244.0, "status": "done"}, {"code": "S = input()\ncount = 0\n\nif S[0] == '1':\n    count += 1\nif S[1] == '1':\n    count += 1\nif S[2] == '1':\n    count += 1\n    \nprint(count)", "passed": true, "time": 0.14, "memory": 14084.0, "status": "done"}, {"code": "s = input()\n \nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14216.0, "status": "done"}, {"code": "S =input()\nprint(S.count('1'))", "passed": true, "time": 0.17, "memory": 14184.0, "status": "done"}, {"code": "s = list(input())\n\nans = 0\n\nfor i in range(len(s)):\n  if s[i] == '1':\n    ans += 1\nelse:\n  print(ans)", "passed": true, "time": 0.14, "memory": 14036.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.17, "memory": 14156.0, "status": "done"}, {"code": "st_list = list(input())\nnu_list = [int(v) for v in st_list]\ncount = 0\nfor i in range(len(nu_list)):\n  if nu_list[i] == 1:\n    count += 1\nprint(count)", "passed": true, "time": 0.14, "memory": 14228.0, "status": "done"}, {"code": "n = input()\nresult = sum(list(map(int,str(n))))\nprint(result)", "passed": true, "time": 0.14, "memory": 14180.0, "status": "done"}, {"code": "s=input()\ncount=0\n\nfor i in range(0,3,1):\n    if s[i]=='1':\n        count = count + 1\n\nprint(count) ", "passed": true, "time": 0.14, "memory": 14164.0, "status": "done"}, {"code": "s=input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14044.0, "status": "done"}, {"code": "# coding: utf-8\n# Your code here!\n\ncnt_1 = 0\n\nlist_S = input()\n\nfor i in list_S : \n    if i == \"1\" : \n        cnt_1 += 1\n        \nprint(cnt_1)", "passed": true, "time": 0.14, "memory": 14104.0, "status": "done"}, {"code": "s = input()\nprint(s.count('1'))", "passed": true, "time": 0.14, "memory": 14260.0, "status": "done"}, {"code": "s = input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14184.0, "status": "done"}, {"code": "s = input().count('1')\nprint(s)", "passed": true, "time": 0.36, "memory": 14272.0, "status": "done"}, {"code": "s = input()\ns_c = s.count(\"1\")\nprint(s_c)", "passed": true, "time": 0.14, "memory": 14060.0, "status": "done"}, {"code": "s = input()\ns1 = int(s[0])\ns2 = int(s[1])\ns3 = int(s[2])\nprint(s1+s2+s3)", "passed": true, "time": 0.14, "memory": 14248.0, "status": "done"}, {"code": "s = input()\nprint(s.count('1'))", "passed": true, "time": 0.31, "memory": 14268.0, "status": "done"}, {"code": "a=str(input())\ncount=0\nfor i in range(3):\n    if a[i-1]==\"1\":\n        count+=1\nprint(count)", "passed": true, "time": 0.15, "memory": 14288.0, "status": "done"}, {"code": "s = input()\nans = 0\nfor i in range(3):\n    if s[i] == \"1\":\n        ans += 1\n\nprint(ans)\n", "passed": true, "time": 0.15, "memory": 14260.0, "status": "done"}, {"code": "s = input()\nans = 0\nfor i in s:\n    ans += int(i)\nprint(ans)", "passed": true, "time": 0.44, "memory": 14048.0, "status": "done"}, {"code": "#!/usr/bin/env python3\nimport sys\nsys.setrecursionlimit(10**6)\n\ns = list(str(input()))\n\nans = [1 if i == \"1\" else 0 for i in s]\n\nprint((sum(ans)))\n", "passed": true, "time": 0.15, "memory": 14104.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14156.0, "status": "done"}, {"code": "s = input()\n\nprint(s.count(\"1\"))", "passed": true, "time": 0.25, "memory": 14200.0, "status": "done"}, {"code": "a=input()\nx=0\nfor i in range(3):\n  if a[i]==\"1\":\n    x=x+1\nprint(x)", "passed": true, "time": 0.14, "memory": 14060.0, "status": "done"}, {"code": "print((input().count('1')))\n", "passed": true, "time": 0.27, "memory": 14160.0, "status": "done"}, {"code": "b = input()\na = str(b)\ni = 0\nif a[0] == '1':\n    i += 1\nif a[1] == '1':\n    i += 1\nif a[2] == '1':\n    i += 1\nprint(i)\n", "passed": true, "time": 0.14, "memory": 14328.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.24, "memory": 14148.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14268.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.15, "memory": 14296.0, "status": "done"}, {"code": "s = list(map(int,input()))\ncount = 0\n\nfor n in s:\n    if n == 1:\n        count+=1\n        \nprint(count)", "passed": true, "time": 0.14, "memory": 14256.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.14, "memory": 14200.0, "status": "done"}, {"code": "s = input()\na, b, c = int(s[0]), int(s[1]), int(s[2])\ncount = 0\nif a == 1:\n  count+=1\nif b == 1:\n  count+=1\nif c == 1:\n  count+=1\nprint(count)", "passed": true, "time": 0.14, "memory": 14084.0, "status": "done"}, {"code": "#\u7b2c2\u554f\u3000ABC081A\nnumber = list(map(int,input()))\na = 0\nfor i in number:\n    if i == 1:\n        a = a+1\nprint(a)", "passed": true, "time": 0.14, "memory": 14076.0, "status": "done"}, {"code": "s = input()\n\nif s == '111':\n    print(3)\nelif s == '110' or s == '101' or s == '011':\n    print(2)\nelif s == '100' or s == '010' or s == '001':\n    print(1)\nelse:\n    print(0)", "passed": true, "time": 0.14, "memory": 14168.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14100.0, "status": "done"}, {"code": "n = input()\nprint(n.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14056.0, "status": "done"}, {"code": "s = str(input())\nprint(s.count('1'))", "passed": true, "time": 0.15, "memory": 14052.0, "status": "done"}, {"code": "a=input()\ncount=0\n\nfor i in range(3):\n  if a[i]=='1':\n  \tcount+=1\n\nprint(count)\n", "passed": true, "time": 0.23, "memory": 14160.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14244.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.14, "memory": 14256.0, "status": "done"}, {"code": "getints = lambda: list(map(int, input().split()))\ns = input()\nans = 0\nfor c in s:\n    if c == '1':\n        ans += 1\nprint(ans)\n", "passed": true, "time": 0.13, "memory": 14068.0, "status": "done"}, {"code": "s = map(int, list(input()))\nprint(sum(s))", "passed": true, "time": 0.14, "memory": 14092.0, "status": "done"}, {"code": "s = input()\nprint(s.count('1'))", "passed": true, "time": 0.14, "memory": 14084.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14184.0, "status": "done"}, {"code": "a = int(input())\n\ncount = 0\n\n# print(int(a/100))\nif int(a / 100) == 1:\n    count += 1\n\n#print(int(a/10 % 10))\nif int(a / 10 % 10) == 1:\n    count += 1\n\n#print(int(a % 100 % 10))\nif int(a % 100 % 10) == 1:\n    count += 1\n\nprint(count)\n", "passed": true, "time": 0.15, "memory": 14244.0, "status": "done"}, {"code": "li = list(input())\nc = 0\nfor i in li:\n    if i == '1':\n        c += 1\n\nprint(c)", "passed": true, "time": 0.14, "memory": 14056.0, "status": "done"}, {"code": "s = str(input())\nans = int(s[0])+int(s[1])+int(s[2])\nprint(ans)", "passed": true, "time": 0.89, "memory": 14276.0, "status": "done"}, {"code": "a = input()\nprint(a.count('1'))", "passed": true, "time": 0.16, "memory": 14148.0, "status": "done"}, {"code": "a = input()\nprint((a.count('1')))\n", "passed": true, "time": 0.27, "memory": 14300.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.19, "memory": 14180.0, "status": "done"}, {"code": "s=list(input())\nres=0\nfor i in s:\n    if (i=='1'):\n        res+=1\nprint(res)", "passed": true, "time": 0.16, "memory": 14280.0, "status": "done"}, {"code": "s = input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14200.0, "status": "done"}, {"code": "A = input()\n\nans=int(0)\n\nif A[0] == \"1\":\n    ans = ans + 1\n\nif A[1] == \"1\":\n    ans = ans + 1\n\nif A[2] == \"1\":\n    ans = ans + 1\n\nprint(ans)", "passed": true, "time": 0.15, "memory": 14240.0, "status": "done"}, {"code": "s=input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.17, "memory": 14028.0, "status": "done"}, {"code": "s = list(input())\ncnt = 0\nfor item in s:\n  if (int(item) == 1):\n    cnt = cnt + 1\nprint(cnt)", "passed": true, "time": 0.14, "memory": 14072.0, "status": "done"}, {"code": "i = str(input())\ns1, s2, s3 = int(i[0]), int(i[1]), int(i[2])\nprint(int(s1+s2+s3))", "passed": true, "time": 0.32, "memory": 14084.0, "status": "done"}, {"code": "D = input()\n\nA=\"1\"\nB=\"11\"\nC=\"101\"\nF=\"111\"\n\nif F == D:\n    print((3))\n    \nelif B in D:\n    print((2))\n\nelif C == D:\n    print((2))\n\nelif A in D:\n    print((1))\n\nelse:\n    print((0))\n", "passed": true, "time": 0.14, "memory": 14092.0, "status": "done"}, {"code": "s = input()\ncnt = 0\n\nif s[0] == '1' : cnt += 1\nif s[1] == '1' : cnt += 1\nif s[2] == '1' : cnt += 1\n\nprint(cnt)\n", "passed": true, "time": 0.14, "memory": 14220.0, "status": "done"}, {"code": "s1,s2,s3 = map(int, input())\n\nnumber_list = [s1,s2,s3]\n\ncounter = 0\n\nfor i in range(len(number_list)):\n    if number_list[i] == 1:\n        counter += 1\nprint(counter)", "passed": true, "time": 0.14, "memory": 14324.0, "status": "done"}, {"code": "s = input()\n\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14276.0, "status": "done"}, {"code": "s=input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14060.0, "status": "done"}, {"code": "s = list(input())\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14184.0, "status": "done"}, {"code": "\n\n# Press the green button in the gutter to run the script.\ndef __starting_point():\n    s = input()\n\n    count = 0\n    for n in range(3):\n        if s[n] == '1':\n            count = count + 1\n\n    print(count)\n\n__starting_point()", "passed": true, "time": 0.14, "memory": 14224.0, "status": "done"}, {"code": "s = input()\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14048.0, "status": "done"}, {"code": "a = input()\n\nb = a.count('1')\nprint(b)", "passed": true, "time": 0.14, "memory": 14276.0, "status": "done"}, {"code": "area = input()\nprint(area.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14276.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.14, "memory": 14152.0, "status": "done"}, {"code": "def main():\n    s = input()\n    print(s.count(\"1\"))\n\n\nmain()", "passed": true, "time": 0.14, "memory": 14248.0, "status": "done"}, {"code": "s = list(input())\n\nprint(s.count('1'))", "passed": true, "time": 0.14, "memory": 14272.0, "status": "done"}, {"code": "def iroha():\n    num = input()\n    count = 0\n\n    for i in num:\n        if i == '1':\n            count+=1\n    \n    print(count)\n\n\ndef __starting_point():\n    iroha()\n\n\n__starting_point()", "passed": true, "time": 0.14, "memory": 14108.0, "status": "done"}, {"code": "a = input()\nprint((a.count('1')))\n", "passed": true, "time": 0.14, "memory": 14024.0, "status": "done"}, {"code": "s = input()\nans = 0\n\nfor i in s:\n    if i == \"1\":\n        ans += 1\n\nprint(ans)", "passed": true, "time": 0.21, "memory": 14068.0, "status": "done"}, {"code": "s = input()\nprint((s.count('1')))\n", "passed": true, "time": 0.2, "memory": 14204.0, "status": "done"}, {"code": "s = input()\nans = 0\nfor i in s:\n    ans += int(i)\nprint(ans)", "passed": true, "time": 0.14, "memory": 14204.0, "status": "done"}, {"code": "s = input()\ncount = 0\nif s[0] == '1':\n  count += 1\nif s[1] == '1':\n  count +=1\nif s[2] == '1':\n  count += 1\nprint(count)", "passed": true, "time": 0.19, "memory": 14188.0, "status": "done"}, {"code": "# \u6587\u5b57\u5217\u306e\u5165\u529b\ns = input()\n\nprint(int(s[0])  + int(s[1])  + int(s[2]))", "passed": true, "time": 0.14, "memory": 14224.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14024.0, "status": "done"}, {"code": "def solve(s):\n    count = 0\n    if s[0] == '1':\n        count += 1\n    if s[1] == '1':\n        count += 1\n    if s[2] == '1':\n        count += 1\n    print(count)\n\n\ndef __starting_point():\n    solve(input())\n\n__starting_point()", "passed": true, "time": 0.14, "memory": 14096.0, "status": "done"}, {"code": "a = input()\nprint(a.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14152.0, "status": "done"}, {"code": "#81\ndata=list(input())\nc=0\nfor i in range(0,len(data)):\n    if data[i]=='1':\n        c=c+1\nprint(c)", "passed": true, "time": 0.14, "memory": 14172.0, "status": "done"}, {"code": "print(input().count('1'))", "passed": true, "time": 0.14, "memory": 14260.0, "status": "done"}, {"code": "print(input().count(\"1\"))", "passed": true, "time": 0.14, "memory": 14292.0, "status": "done"}, {"code": "s = input()\n\nprint(s.count(\"1\"))", "passed": true, "time": 0.14, "memory": 14068.0, "status": "done"}, {"code": "s = input()\n \ncnt = sum([int(c) for c in s])\nprint(cnt)", "passed": true, "time": 0.14, "memory": 14244.0, "status": "done"}]