func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     string arr[n], mx =  2011 ;     for (int i = 0; i < n; i++) cin >> arr[i];     for (int p = n - 1; p >= 0; p--) {       string maxi =  0000 ;       for (int i = 0; i <= 3; i++) {         char s = arr[p][i];         for (int j = 9; j >= 0; j--) {           arr[p][i] = char( 0  + j);           if (arr[p] <= mx && arr[p] >=  1000 ) {             if (arr[p] > maxi) maxi = arr[p];           }         }         arr[p][i] = s;       }       if (maxi ==  0000 ) {         cout <<  No solution  << endl;         return 0;       }       arr[p] = maxi;       mx = maxi;     }     for (int i = 0; i < n; i++) {       cout << arr[i] << endl;     }   }   