import sys
input = lambda: sys.stdin.readline().rstrip()

def main():
    a, p = map(int, input().split())
    print((a * 3 + p) // 2)
    
if __name__ == '__main__':
    main() import sys sys input = lambda: sys.stdin.readline().rstrip() input lambda: sys.stdin.readline().rstrip() sys.stdin.readline().rstrip() sys.stdin.readline().rstrip sys.stdin.readline() sys.stdin.readline sys.stdin sys stdin readline rstrip def main():
    a, p = map(int, input().split())
    print((a * 3 + p) // 2)
     main a, p = map(int, input().split()) a map(int, input().split()) map int input().split() ().split () input split p print((a * 3 + p) // 2) print (a * 3 + p) // 2 a * 3 + p a * 3 a 3 p 2 if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main input = lambda: sys.stdin.readline().rstrip() lambda: sys.stdin.readline().rstrip() input def main():
    a, p = map(int, input().split())
    print((a * 3 + p) // 2)
     def main():
    a, p = map(int, input().split())
    print((a * 3 + p) // 2)
     main
import sys
input = lambda: sys.stdin.readline().rstrip()

def main():
    a, p = map(int, input().split())
    print((a * 3 + p) // 2)
    
if __name__ == '__main__':
    main()