#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  while (t--) {
    int n, k;
    cin >> n >> k;
    string str;
    cin >> str;
    int pos = -1;
    for (int i = 1; i < n; i++) {
      int start = 0;
      for (int j = i; j < n; j++) {
        if (str[j] == str[start]) {
          start++;
        } else {
          start = 0;
          break;
        }
      }
      if (start != 0) {
        pos = i;
        break;
      }
    }
    string ans = str;
    if (pos != -1) {
      ans = str.substr(n - pos, pos);
    }
    cout << str;
    for (int i = 0; i < k - 1; i++) {
      cout << ans;
    }
  }
  return 0;
}
