def ABC_128_A():
    A,P = map(int, input().split())
    print(int((A*3+P)/2))


if __name__ == '__main__':

    ABC_128_A() def ABC_128_A():
    A,P = map(int, input().split())
    print(int((A*3+P)/2)) ABC_128_A A,P = map(int, input().split()) A map(int, input().split()) map int input().split() ().split () input split P print(int((A*3+P)/2)) print int((A*3+P)/2) int (A*3+P)/2 A*3+P A*3 A 3 P 2 if __name__ == '__main__':

    ABC_128_A() __name__ == '__main__' __name__ '__main__' ABC_128_A() ABC_128_A def ABC_128_A():
    A,P = map(int, input().split())
    print(int((A*3+P)/2)) def ABC_128_A():
    A,P = map(int, input().split())
    print(int((A*3+P)/2)) ABC_128_A
def ABC_128_A():
    A,P = map(int, input().split())
    print(int((A*3+P)/2))


if __name__ == '__main__':

    ABC_128_A()