#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
const long long LINF = 1e18;
const int MOD = 1e9 + 7;
int main() {
  int a, p;
  cin >> a >> p;
  cout << (3 * a + p) + 1 / 2 << endl;
}
