#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  for (char j = 'a'; j <= 'z'; j++) {
    for (int i = 0; k > 0 && i < s.length();) {
      if (s[i] == j) {
        s.erase(i, 1);
        i = i;
        k--;
      } else
        i++;
    }
    if (k <= 0) break;
  }
  cout << s << endl;
  return 0;
}
