#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[30] = {0}, b[30] = {0};
  int n, k;
  string str;
  cin >> n >> k >> str;
  for (int i = 0; i < str.size(); i++) {
    a[str[i] - 'a']++;
    b[str[i] - 'a']++;
  }
  for (int i = 0; i < 26; i++) {
    if (a[i] <= k) {
      k = k - a[i];
      a[i] = 0;
    } else {
      a[i] -= k;
      k = 0;
    }
    if (k == 0) break;
  }
  if (k > 0) return 0;
  for (int i = 0; i < str.size(); i++) {
    if (a[str[i] - 'a'] < b[str[i] - 'a']) {
      a[str[i] - 'a']++;
    } else
      cout << str[i];
  }
  return 0;
}
