#include <bits/stdc++.h>
using namespace std;
const int N = 4e5 + 5;
char a[N];
int main() {
  int n, k;
  while (cin >> n >> k) {
    scanf("%s", a);
    for (int i = 0; i < 26; i++) {
      for (int j = 0; j < n; j++) {
        if (a[j] == 'a' + i) {
          a[j] = '0';
          k--;
        }
        if (k == 0) {
          goto end;
        }
      }
    }
  end:
    for (int i = 0; i < n; i++) {
      if (a[i] - '0') {
        printf("%c", a[i]);
      }
    }
    cout << endl;
  }
  return 0;
}
