#include <bits/stdc++.h>
using namespace std;
map<char, int> freq;
vector<int> vec;
vector<char> vec2;
int main() {
  int n, k;
  cin >> n >> k;
  string s, ans, update, alpha = "abcdefghijklmnopqrstuvwxyz";
  cin >> s;
  int size = s.size();
  for (int i = 0; i < 26; i++) {
    for (int j = 0; j < size; j++) {
      if (k > 0) {
        if (s[j] == alpha[i]) {
          k--;
          s[j] = '0';
        }
      }
    }
  }
  for (int i = 0; i < size; i++) {
    if (s[i] != '0') {
      ans += s[i];
    }
  }
  cout << ans << endl;
  return 0;
}
