#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  char str[n + 1];
  cin >> str;
  int n_alphs[26];
  for (int i = 0; i < 26; i++) n_alphs[i] = 0;
  for (int i = 0; i < n; i++) {
    n_alphs[(int)(str[i]) - 97]++;
  }
  int count = k;
  int left = 0;
  for (int i = 0; i < 26; i++) {
    if (n_alphs[i] <= count)
      count -= n_alphs[i];
    else {
      left = i;
      break;
    }
    if (count == 0) {
      left = i + 1;
      break;
    }
  }
  char new_str[n + 1];
  int last_count = 0, j = 0;
  for (int i = 0; i < n; i++) {
    if ((int)(str[i]) - 97 < left)
      continue;
    else if ((int)(str[i]) - 97 == left) {
      if (last_count < count) {
        last_count++;
        continue;
      } else {
        new_str[j] = str[i];
        j++;
      }
    } else {
      new_str[j] = str[i];
      j++;
    }
  }
  new_str[j] = '\0';
  cout << new_str << "\n";
  return 0;
}
