#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  string s;
  cin >> n >> k >> s;
  std::vector<int> v(26, 0);
  for (int i = 0; i < n; i++) v[s[i] - 'a']++;
  int i = 0, sum = 0;
  for (i = 0; i < 26 && k > v[i]; i++) k -= v[i];
  for (int j = 0; j < n; j++)
    if ((s[j] - 'a') < i)
      s[j] = '.';
    else if ((s[j] - 'a') == i && k)
      k--, s[j] = '.';
  for (int j = 0; j < n; j++)
    if (s[j] != '.') cout << s[j];
  cout << endl;
  ;
  return 0;
}
