#include <bits/stdc++.h>
using namespace std;
const int maxn = 4e5 + 5;
char s[maxn];
int coun[26], now[26];
int main() {
  int n, k;
  while (~scanf("%d %d", &n, &k)) {
    scanf("%s", s);
    memset(coun, 0, sizeof(coun));
    memset(now, 0, sizeof(now));
    for (int i = 0; i < n; i++) coun[s[i] - 'a']++;
    for (int i = 0; i < 26; i++) {
      if (coun[i] < k) {
        now[i] = coun[i];
        k -= coun[i];
      } else {
        now[i] = k;
        break;
      }
    }
    for (int i = 0; i < n; i++) {
      if (now[s[i] - 'a']) {
        now[s[i] - 'a']--;
      } else {
        printf("%c", s[i]);
      }
    }
    printf("\n");
  }
  return 0;
}
