#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, k, n;
  string s;
  vector<pair<int, int> > v;
  cin >> n >> k;
  cin >> s;
  for (i = 0; i < n; i++) {
    j = s[i] - 'a';
    v.push_back(make_pair(j, i));
  }
  sort(v.begin(), v.end());
  int arr[n];
  for (i = 0; i < n; i++) {
    arr[i] = 0;
  }
  for (i = 0; i < k; i++) {
    arr[v[i].second] = 1;
  }
  for (i = 0; i < n; i++) {
    if (arr[i] == 0) cout << s[i];
  }
}
