#include <bits/stdc++.h>
using namespace std;

int main() {
  int A,P;
  cin >> A >> P;
  cout << (A*3+P)/2 << endl;
}#include <bits/stdc++.h>
using namespace std;

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