#include <bits/stdc++.h>
int main() {
  int a, b, c;
  std::cin >> a >> b >> c;
  int weeks = std::min(a / 3, std::min(b / 2, c / 2));
  a -= weeks * 3;
  b -= weeks * 2;
  c -= weeks * 2;
  int ans(0);
  for (int i = 1; i <= 7; ++i) {
    int ac = a;
    int bc = b;
    int cc = c;
    int zile(0);
    int curr_zi = i;
    while (ac || bc || cc) {
      ++zile;
      if (curr_zi == 8) curr_zi -= 7;
      if (curr_zi == 1) {
        ac--;
      } else if (curr_zi == 2) {
        bc--;
      } else if (curr_zi == 3) {
        cc--;
      } else if (curr_zi == 4) {
        ac--;
      } else if (curr_zi == 5) {
        cc--;
      } else if (curr_zi == 6) {
        bc--;
      } else {
        ac--;
      }
      if (ac < 0 || bc < 0 || cc < 0) {
        zile--;
        break;
      }
      curr_zi++;
    }
    ans = std::max(ans, zile);
  }
  std::cout << weeks * 7 + ans;
}
