#include <bits/stdc++.h>
using namespace std;
int cnt[300007];
int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  string s;
  cin >> s;
  int check = 100;
  for (int i = (0); i <= ((int)s.size() - 1); ++i) ++cnt[s[i] - 'a'];
  for (int i = ('a'); i <= ('z'); ++i) {
    if (k >= cnt[i - 'a'])
      k -= cnt[i - 'a'];
    else {
      cnt[i - 'a'] -= k;
      check = i - 'a';
      break;
    }
  }
  string str = "";
  for (int i = (0); i <= ((int)s.size() - 1); ++i) {
    if (s[i] - 'a' < check) continue;
    if (s[i] - 'a' == check) {
      if (k) {
        --k;
        continue;
      }
    }
    str += s[i];
  }
  cout << str << endl;
  return 0;
}
