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

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

main()
