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