func_code_string: #include <bits/stdc++.h>   using namespace std;   string s;   int n, ans = 0;   vector<pair<int, int>> b;   vector<int> a(26);   int main() {     cin >> s >> n;     for (int i = 0; i < s.length(); ++i) {       a[s[i] -  a ]++;     }     for (int i = 0; i < 26; ++i) {       b.push_back(make_pair(a[i], i));     }     sort(b.begin(), b.end());     for (int i = 0; i < 26; ++i) {       if (n >= b[i].first) {         n -= b[i].first;         b[i].first = 0;       }     }     for (int i = 0; i < 26; ++i) {       if (b[i].first != 0) ans++;     }     cout << ans << endl;     for (int i = 0; i < s.length(); ++i) {       for (int j = 0; j < 26; ++j) {         if (s[i] -  a  == b[j].second && b[j].first > 0) {           cout << s[i];         }       }     }     return 0;   }   