func_code_string: #include <bits/stdc++.h>   using namespace std;   int a, b, c, d;   int main() {     cin >> a >> b >> c >> d;     if (c - d < -1 || c - d > 1 || a < max(c, d) || b < max(c, d)) {       cout << -1;       return 0;     }     if (c - d == -1) {       for (int i = 0; i < d; i++) {         if (i == d - 1)           for (int j = b; j > d; j--) cout << 7;         cout << 74;         if (!i)           for (int j = a; j > d; j--) cout << 4;       }     }     if (c - d == 1) {       for (int i = a; i > c; i--) cout << 4;       for (int i = 0; i < c; i++) cout << 47;       for (int i = b; i > c; i--) cout << 7;     }     if (c == d) {       if (a == c && b == d) {         cout << -1;         return 0;       }       if (a > c) {         for (int i = a; i > c + 1; i--) cout << 4;         for (int i = 0; i < c; i++) {           cout << 47;         }         for (int i = b; i > d; i--) cout << 7;         cout << 4;       } else {         cout << 7;         for (int i = 0; i < c; i++) cout << 47;         for (int i = b; i > d + 1; i--) cout << 7;       }     }   }   