#include <bits/stdc++.h>
using namespace std;
string a;
int b[26], c[26];
int main() {
  int n, k, i, m;
  cin >> n >> k;
  cin >> a;
  for (i = 0; i < n; i++) {
    b[a[i] - 97]++;
  }
  for (i = 0, m = k; m != 0; i++) {
    while (b[i] != 0) {
      c[i]++;
      b[i]--;
      m--;
      if (m == 0) break;
    }
  }
  for (i = 0; i < a.size(); i++) {
    if (c[a[i] - 97] != 0) {
      c[a[i] - 97]--;
    } else
      cout << a[i];
  }
  return 0;
}
