#include <bits/stdc++.h>
using std::cerr;
using std::cin;
using std::cout;
using std::endl;
using std::make_pair;
using std::pair;
int main() {
  std::ios::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  std::string s;
  cin >> s;
  int t = n + 1, len = n;
  for (int i = 1; i < len; ++i) {
    bool flag = true;
    for (int j = 0, k = len - i; j < i; ++j, ++k) {
      if (s[j] != s[k]) {
        flag = false;
        break;
      }
    }
    if (flag) t = i;
  }
  if (t == n + 1) {
    for (register int i = (1); i <= (k); ++i) cout << s;
    return 0;
  }
  std::string s_out = s.substr(t, n - t);
  cout << s;
  --t;
  for (register int i = (2); i <= (k); ++i) {
    cout << s_out;
  }
  return 0;
}
