#include <bits/stdc++.h>
using namespace std;
int main(void) {
  vector<vector<int>> strmap(27);
  int n, k;
  char str[400001], ans[400010] = {0};
  scanf("%d%d", &n, &k);
  scanf("%s", str);
  for (int i = 0; i < n; i++) strmap[str[i] - 'a'].push_back(i);
  for (char i = 'a'; k and i <= 'z'; i++) {
    int cnt = strmap[i - 'a'].size();
    if (cnt) {
      for (int x = 0; x < min(cnt, k); x++) {
        str[strmap[i - 'a'][x]] = 0;
      }
      k -= min(cnt, k);
    }
  }
  for (int i = 0; i < n; i++)
    if (str[i]) putchar(str[i]);
  putchar('\n');
  return 0;
}
