#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  int a[160];
  for (int j = 0; j < 100; j++) {
    a[j] = 0;
  }
  for (int j = 0; j < n; j++) {
    a[s[j] - 'a' + 1]++;
  }
  int tp = k, idx = 0;
  for (int j = 1; j <= 26; j++) {
    tp = tp - a[j];
    if (tp <= 0) {
      tp = tp + a[j];
      idx = j;
      break;
    }
  }
  string str;
  for (int j = 0; j < n; j++) {
    if (s[j] == (idx + 96) && tp > 0) {
      tp--;
    } else if (s[j] == (idx + 96) && tp <= 0) {
      str.push_back(s[j]);
    }
    if (s[j] > (idx + 96)) {
      str.push_back(s[j]);
    }
  }
  cout << str << "\n";
  return 0;
}
