#include <bits/stdc++.h>
using namespace std;
map<char, int> wakaka;
bool Exit[400005];
int main() {
  int n, t;
  cin >> n >> t;
  string s;
  cin >> s;
  memset(Exit, false, sizeof(Exit));
  for (int i = 0; i < n; i++) {
    wakaka[s[i]]++;
  }
  int temp = -1;
  while (t) {
    temp++;
    char str = char(temp + 97);
    if (wakaka[str] == 0) continue;
    for (int i = 0; i < s.length(); i++) {
      if (t == 0) break;
      if (s[i] == str && Exit[i] == false) {
        Exit[i] = true;
        t--;
      }
    }
  }
  for (int i = 0; i < s.length(); i++) {
    if (Exit[i] == false) cout << s[i];
  }
  cout << endl;
  return 0;
}
