import sys

a, p = map(int, sys.stdin.readline().split())

def main():
    res = (3 * a + p) // 2
    print(res)

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

a, p = map(int, sys.stdin.readline().split())

def main():
    res = (3 * a + p) // 2
    print(res)

if __name__ ==  '__main__':
    main()