#include <bits/stdc++.h>
using namespace std;
string greedy(string s, int k) {
  int n = s.size();
  while (k > 1) {
    int take = 1;
    while (take < n && s[n - take - 1] == s[n - 1]) take++;
    string t = "";
    for (int i = 0; i < n - take; i++) t += s[take + i];
    for (int i = 0; i < take; i++) t += s[n - i - 1];
    s = t;
    k--;
  }
  int take = 1;
  while (take < n && s[n - take - 1] == s[n - 1]) take++;
  string t = "";
  for (int i = 0; i < take; i++) t += s[n - take + i];
  for (int i = 0; i < n - take; i++) t += s[n - i - 1];
  return t;
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  k = min(k, 15);
  string res = "";
  for (int i = 0; i < n; i++) res += 'z';
  string t = s;
  reverse(t.begin(), t.end());
  s += t;
  for (int i = 0; i <= n; i++) {
    string var = "";
    for (int j = 0; j < n; j++) var += s[i + j];
    res = min(res, greedy(var, k - 1));
  }
  cout << res;
}
