#include <bits/stdc++.h>
using namespace std;
bool f[400001];
signed main() {
  string s;
  int n, k;
  cin >> n >> k;
  cin >> s;
  for (char c = 'a'; c <= 'z'; c++)
    for (int i = 0; i < n; i++)
      if (s[i] == c && k > 0) {
        k--;
        f[i] = 1;
      }
  for (int i = 0; i < n; i++)
    if (!f[i]) cout << s[i];
}
