#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  int l = s.length();
  int arr[26];
  int nrr[26];
  memset(arr, 0, sizeof(arr));
  memset(nrr, 0, sizeof(nrr));
  for (int i = 0; i < l; i++) {
    arr[s[i] - 'a']++;
    nrr[s[i] - 'a']++;
  }
  int j = 0;
  for (int i = 0; i < 26; i++) {
    if (k == 0) {
      break;
    }
    if (nrr[i] <= k) {
      k -= nrr[i];
      nrr[i] = 0;
    } else {
      nrr[i] -= k;
      break;
    }
  }
  for (int i = 0; i < l; i++) {
    if (arr[s[i] - 'a'] == nrr[s[i] - 'a']) {
      cout << s[i];
    } else {
      arr[s[i] - 'a']--;
    }
  }
}
