import math
p,q= input().split()
a,b =(int(p), int(q))
b += a*3
n = b/2
print(math.floor(n)) import math math p,q= input().split() p input().split() ().split () input split q a,b =(int(p), int(q)) a (int(p), int(q)) int(p) int p int(q) int q b b += a*3 b a*3 a 3 n = b/2 n b/2 b 2 print(math.floor(n)) print math.floor(n) math.floor math floor n p,q= input().split() input().split() p a,b =(int(p), int(q)) (int(p), int(q)) a n = b/2 b/2 n q= input().split() input().split() q b =(int(p), int(q)) (int(p), int(q)) b b += a*3 a*3 b
import math
p,q= input().split()
a,b =(int(p), int(q))
b += a*3
n = b/2
print(math.floor(n))