func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     int n, k;     cin >> n >> k;     string s;     cin >> s;     set<char> ST;     for (char x : s) ST.insert(x);     if (k > n) {       for (int i = 0; i < n; i++) cout << s[i];       for (int i = n; i < k; i++) cout << *ST.begin();       return;     }     for (int i = k - 1; i >= 0; i--) {       if (s[i] < *ST.rbegin()) {         string f =   ;         for (int j = 0; j < i; j++) f += s[j];         char mnThatWorkz =  z ;         for (char c : ST) {           if (c > s[i] && mnThatWorkz > c) mnThatWorkz = c;         }         f += mnThatWorkz;         while ((int)f.size() < k) f += *ST.begin();         cout << f <<   n ;         return;       }     }   }   int32_t main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     int t = 1;     while (t--) {       solve();     }   }   