// This file is a "Hello, world!" in C++ language by GCC for wandbox.
#include <iostream>
#include <cstdlib>

int main()
{
   int A;
    int P;
    int m;
    cin>>A>>P;
    P=P+3*A;
   m=P/2;
    cout<<m;
}

// GCC reference:
//   https://gcc.gnu.org/

// C++ language references:
//   https://cppreference.com/
//   https://isocpp.org/
//   http://www.open-std.org/jtc1/sc22/wg21/

// Boost libraries references:
//   https://www.boost.org/doc/

