#include <bits/stdc++.h>
using namespace std;
const int maxn = 4e5 + 10;
int num[27];
int reduce[27];
int main() {
  ios::sync_with_stdio(false);
  int n, k;
  string str;
  cin >> n >> k;
  cin >> str;
  memset(num, 0, sizeof(num));
  memset(reduce, 0, sizeof(reduce));
  for (int i = 0; i < n; i++) {
    num[str[i] - 'a']++;
  }
  int tot = 0;
  while (k > 0) {
    if (k >= num[tot]) {
      reduce[tot] = num[tot];
      k -= num[tot];
      tot++;
    } else {
      reduce[tot] = k;
      num[tot] -= k;
      k = 0;
      tot++;
    }
  }
  for (int i = 0; i < n; i++) {
    if (reduce[str[i] - 'a']) {
      reduce[str[i] - 'a']--;
      continue;
    } else {
      cout << str[i];
    }
  }
  cout << endl;
  cin >> str;
  return 0;
}
