#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
const int dir_4[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
const int dir_8[8][2] = {{1, 0},  {1, 1},   {0, 1},  {-1, 1},
                         {-1, 0}, {-1, -1}, {0, -1}, {1, -1}};
const long long mod = 1e9 + 7;
int main() {
  int n, x;
  cin >> n >> x;
  cout << 7 * x / 2 + n << endl;
  return 0;
}
