func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MX = (1 << 19);   string str;   vector<pair<int, char> > sorted;   int cnt[MX], done[MX], K;   int main() {     cin >> str >> K;     for (int j = 0; j < str.size(); j++) cnt[str[j] -  a ]++;     for (int j = 0; j < 26; j++) {       sorted.push_back(make_pair(cnt[j], j +  a ));     }     sort(sorted.begin(), sorted.end());     int ans = 26;     for (auto pp : sorted) {       if (pp.first > K) break;       K -= pp.first;       done[pp.second] = 1;       --ans;     }     cout << ans << endl;     for (auto ch : str)       if (!done[ch]) cout << ch;     cout << endl;   }   