#include <bits/stdc++.h>   using namespace std;   int main() {     int a, b, c, cc = 0;     cin >> a >> b >> c;     if (a < 0 || b < 2 || c < 4)       cout << 0 << endl;     else {       while (a >= 1 && b >= 2 && c >= 4) {         cc++;         a--;         b -= 2;         c -= 4;       }       cout << cc * 7 << endl;     }     return 0;   }   