from sys import stdin, setrecursionlimit


def main():
    input = stdin.buffer.readline
    a, p = map(int, input().split())
    print((3 * a + p) // 2)


if __name__ == "__main__":
    setrecursionlimit(10000)
    main() from sys import stdin, setrecursionlimit def main():
    input = stdin.buffer.readline
    a, p = map(int, input().split())
    print((3 * a + p) // 2) main input = stdin.buffer.readline input stdin.buffer.readline stdin.buffer stdin buffer readline a, p = map(int, input().split()) a map(int, input().split()) map int input().split() ().split () input split p print((3 * a + p) // 2) print (3 * a + p) // 2 3 * a + p 3 * a 3 a p 2 if __name__ == "__main__":
    setrecursionlimit(10000)
    main() __name__ == "__main__" __name__ "__main__" setrecursionlimit(10000) setrecursionlimit 10000 main() main def main():
    input = stdin.buffer.readline
    a, p = map(int, input().split())
    print((3 * a + p) // 2) def main():
    input = stdin.buffer.readline
    a, p = map(int, input().split())
    print((3 * a + p) // 2) main
from sys import stdin, setrecursionlimit


def main():
    input = stdin.buffer.readline
    a, p = map(int, input().split())
    print((3 * a + p) // 2)


if __name__ == "__main__":
    setrecursionlimit(10000)
    main()
