#include <bits/stdc++.h>
using namespace std;
template <class T>
using V = vector<T>;
using ll = long long;
using db = double;
using st = string;
using ch = char;
using vll = V<ll>;
using vpll = V<pair<ll, ll>>;
using vst = V<st>;
using vdb = V<db>;
using vch = V<ch>;
int main() {
  ll n, m;
  cin >> n >> m;
  ;
  cout << (3 * n + 2 * m) / 2 << endl;
}
