#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, i, j, k, n;
  cin >> n >> k;
  string s;
  cin >> s;
  map<char, vector<int>> m, m1;
  for (i = 0; i < n; i++) {
    m1[s[i]].push_back(i);
  }
  char ch;
  for (ch = 'a'; ch <= 'z'; ch++) {
    if (m1[ch].size() <= k) {
      k -= m1[ch].size();
    } else {
      break;
    }
  }
  for (i = 0; i < s.size(); i++) {
    if (s[i] < ch) {
      continue;
    }
    if (k > 0 && s[i] == ch) {
      k--;
    } else
      cout << s[i];
  }
  return 0;
}
