func_code_string: #include <bits/stdc++.h>   using namespace std;   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     long long n;     cin >> n;     long long now = 0;     long long mx = -1;     while (true) {       long long rem = (n - (now * 7));       if (rem < 0) {         break;       } else {         if (rem % 4 == 0) {           mx = max(mx, now);         }       }       now++;     }     if (mx == -1) {       cout << -1;       return 0;     } else {       long long four = n - (mx * 7);       four /= 4;       for (long long i = 0; i < four; i++) {         cout << 4;       }       for (long long i = 0; i < mx; i++) {         cout << 7;       }     }   }   