#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 * 4 + 5;
queue<int> i[30];
int main() {
  int n, m, a, j[30], b;
  char st[maxn];
  bool bo[maxn];
  memset(bo, 0, sizeof(bo));
  memset(j, 0, sizeof(j));
  scanf("%d %d%*c", &n, &m);
  scanf("%s", st);
  for (a = 1; a <= 26; a++)
    while (!i[a].empty()) {
      i[a].pop();
    }
  for (a = 0; a <= n - 1; a++) {
    i[st[a] - 'a' + 1].push(a);
    j[st[a] - 'a' + 1]++;
  }
  b = 1;
  for (a = 1; a <= m; a++) {
    if (b <= 26) {
      while (j[b] < 1 && b <= 26) {
        b++;
      }
      if (b <= 26) {
        bo[i[b].front()] = true;
        i[b].pop();
        j[b]--;
      }
    }
  }
  for (a = 0; a < n; a++)
    if (!bo[a]) printf("%c", st[a]);
  return 0;
}
