def solve():
    N, M = map(int, input().split())
    return (N*3+M) // 2

print(solve()) def solve():
    N, M = map(int, input().split())
    return (N*3+M) // 2 solve N, M = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split M return (N*3+M) // 2 (N*3+M) // 2 N*3+M N*3 N 3 M 2 print(solve()) print solve() solve def solve():
    N, M = map(int, input().split())
    return (N*3+M) // 2 def solve():
    N, M = map(int, input().split())
    return (N*3+M) // 2 solve
def solve():
    N, M = map(int, input().split())
    return (N*3+M) // 2

print(solve())