func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long t;     cin >> t;     while (t--) {       long long n;       cin >> n;       map<string, int> m;       int ans = 0;       vector<string> a, b;       for (int i = 0; i < n; i++) {         string s;         cin >> s;         if (m[s] != 0) ans++;         m[s]++;         b.push_back(s);       }       for (int i = 0; i < n; i++) {         string s;         s = b[i];         if (m[s] != 1) {           m[s]--;           while (true) {             if (s[3] ==  9 )               s[3] =  0 ;             else               s[3] = ((int)s[3] + 1);             if (m[s] == 0) {               m[s]++;               a.push_back(s);               break;             }           }         } else {           a.push_back(s);         }       }       cout << ans << endl;       for (int i = 0; i < a.size(); i++) {         cout << a[i] << endl;       }     }     return 0;   }   