#include <bits/stdc++.h>
using namespace std;
int n, k;
string s;
void solve() {
  cin >> n >> k >> s;
  for (int i = 0; i < 26; i++) {
    for (int j = 0; j < n; j++) {
      if (s[j] == 'a' + i) {
        k--;
        s[j] = '#';
      }
      if (k == 0) {
        break;
      }
    }
    if (k == 0) {
      break;
    }
  }
  for (int i = 0; i < n; i++) {
    if (s[i] != '#') {
      cout << s[i];
    }
  }
}
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
