INT = lambda: int(input())
INTM = lambda: map(int,input().split())
STRM = lambda: map(str,input().split())
STR = lambda: str(input())
LIST = lambda: list(map(int,input().split()))
LISTS = lambda: list(map(str,input().split()))
def do():
    a,p=INTM()
    print((3*a+p)//2)
if __name__ == '__main__':
    do() INT = lambda: int(input()) INT lambda: int(input()) int(input()) int input() input INTM = lambda: map(int,input().split()) INTM lambda: map(int,input().split()) map(int,input().split()) map int input().split() ().split () input split STRM = lambda: map(str,input().split()) STRM lambda: map(str,input().split()) map(str,input().split()) map str input().split() ().split () input split STR = lambda: str(input()) STR lambda: str(input()) str(input()) str input() input LIST = lambda: list(map(int,input().split())) LIST lambda: list(map(int,input().split())) list(map(int,input().split())) list map(int,input().split()) map int input().split() ().split () input split LISTS = lambda: list(map(str,input().split())) LISTS lambda: list(map(str,input().split())) list(map(str,input().split())) list map(str,input().split()) map str input().split() ().split () input split def do():
    a,p=INTM()
    print((3*a+p)//2) do a,p=INTM() a INTM() INTM p print((3*a+p)//2) print (3*a+p)//2 3*a+p 3*a 3 a p 2 if __name__ == '__main__':
    do() __name__ == '__main__' __name__ '__main__' do() do INT = lambda: int(input()) lambda: int(input()) INT INTM = lambda: map(int,input().split()) lambda: map(int,input().split()) INTM STR = lambda: str(input()) lambda: str(input()) STR LISTS = lambda: list(map(str,input().split())) lambda: list(map(str,input().split())) LISTS def do():
    a,p=INTM()
    print((3*a+p)//2) def do():
    a,p=INTM()
    print((3*a+p)//2) do LIST = lambda: list(map(int,input().split())) lambda: list(map(int,input().split())) LIST STRM = lambda: map(str,input().split()) lambda: map(str,input().split()) STRM
INT = lambda: int(input())
INTM = lambda: map(int,input().split())
STRM = lambda: map(str,input().split())
STR = lambda: str(input())
LIST = lambda: list(map(int,input().split()))
LISTS = lambda: list(map(str,input().split()))
def do():
    a,p=INTM()
    print((3*a+p)//2)
if __name__ == '__main__':
    do()