#include <bits/stdc++.h>
using namespace std;
void rev(string& s, int st, int len) {
  for (int i = st; i < st + len / 2; ++i)
    swap(s[i], s[st + len - 1 - (i - st)]);
}
int main() {
  int n, k;
  string s;
  cin >> n >> k >> s;
  bool* u = new bool[n];
  for (int i = 0; i < n; ++i) u[i] = true;
  for (char c = 'a'; c <= 'z' && k; ++c)
    for (int i = 0; i < n && k; ++i)
      if (s[i] == c) {
        u[i] = false;
        --k;
      }
  for (int i = 0; i < n; ++i)
    if (u[i]) cout << s[i];
}
