#include <bits/stdc++.h>
using namespace std;
string a[51], b[51];
char s[2002];
int n, k;
int main() {
  scanf("%d%d", &n, &k);
  scanf("%s", s);
  for (int i = 0; i < n; i++) a[i + 1] = a[i] + s[i];
  for (int i = n - 1; i >= 0; i--) b[i + 1] = s[i] + b[i + 2];
  int ans = 0;
  for (int i = n - 1; i >= 1; i--)
    if (a[i] == b[n + 1 - i]) ans = max(i, ans);
  for (int j = 1; j < k; j++)
    for (int i = 1; i <= n - ans; i++) cout << s[i - 1];
  for (int i = 1; i <= n; i++) cout << s[i - 1];
  return 0;
}
