#include <bits/stdc++.h>
using namespace std;
string singleOperation(string s, int n) {
  string res = s;
  for (int i = n - 1; i >= 0; i--) s += s[i];
  for (int i = 1; i <= n; i++) res = min(res, s.substr(i, n));
  return res;
}
string doubleOperations(string s, int n) {
  string res = s;
  for (int i = n - 1; i >= 0; i--) s += s[i];
  string candidate = "{";
  for (int i = 1; i <= n; i++) {
    string u = s.substr(i, n);
    reverse(u.begin(), u.end());
    candidate = min(candidate, u);
  }
  reverse(candidate.begin(), candidate.end());
  return singleOperation(candidate, n);
}
int main() {
  int n, k;
  string s;
  cin >> n >> k >> s;
  for (int i = 0; i < min(15, k / 2); i++) s = doubleOperations(s, n);
  if (k % 2) s = singleOperation(s, n);
  cout << s << endl;
}
