#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int n, k;
  cin >> n >> k;
  string s, st = "";
  cin >> s;
  vector<int> m(28);
  vector<int> l(28);
  for (int i = 0; i < n; i++) {
    m[((int)s[i]) - 97]++;
  }
  if (n == k) {
    cout << "\n";
    return 0;
  }
  while (k > 0) {
    for (int i = 0; i < 27; i++) {
      if (k >= m[i]) {
        k -= m[i];
        l[i] = m[i];
      } else {
        m[i] = k;
        l[i] = k;
        k = 0;
      }
      if (k == 0) {
        break;
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (l[((int)s[i]) - 97] > 0) {
      l[((int)s[i]) - 97]--;
      continue;
    } else
      cout << s[i];
  }
  return 0;
}
