func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int count = 0;     char k[4];     cin >> k;     int a[5];     for (int i = 0; i < 4; i++) {       a[i] = k[i] -  0 ;     }     int b[5];     for (int i = 0; i < 4; i++) {       b[i] = a[i];     }     while (1) {       if (b[3] == 9) {         b[3] = 0;         if (b[2] == 9) {           b[2] = 0;           if (b[1] == 9) {             b[1] = 0;             b[0] = b[0] + 1;           } else             b[1] = b[1] + 1;         } else           b[2] = b[2] + 1;       } else         b[3] = b[3] + 1;       int i = 0;       for (int v = 0; v < 4; v++)         for (int z = v + 1; z < 4; z++) {           if (b[v] == b[z]) count++;         }       if (count == 0)         break;       else         count = 0;     }     for (int m = 0; m < 4; m++) {       cout << b[m];     }   }   