#include <bits/stdc++.h>
using namespace std;
char s[400005];
int a[130] = {0};
int main() {
  int n, k;
  cin >> n >> k;
  cin >> s;
  for (int i = 0; i < n; i++) a[s[i]]++;
  int sum = 0, f, o;
  for (int i = 'a'; i <= 'z'; i++) {
    sum += a[i];
    if (sum > k) {
      f = i;
      o = k - (sum - a[i]);
      break;
    } else if (sum == k) {
      f = i;
      break;
    }
  }
  for (int i = 0, w = 0, qq = 0; i < n; i++) {
    if ((int)(s[i]) < f && w < k)
      w++;
    else if ((int)(s[i]) == f && w < k && qq < o)
      qq++, w++;
    else
      cout << s[i];
  }
  return 0;
}
