#include <bits/stdc++.h>
using namespace std;
int main() {
  char t[51];
  int n, k;
  int i, j;
  int lb = 0, ub = 0;
  int lf, uf = 0;
  scanf("%d %d %s", &n, &k, t);
  while (lb + ub < n) {
    ub = 0;
    while (lb < n && t[++lb] != t[0])
      ;
    while (lb + ++ub < n && t[ub + lb] == t[ub])
      ;
  }
  for (i = 0; i < k; i++) {
    for (j = 0; j < lb; j++) {
      printf("%c", t[j]);
    }
  }
  for (i = lb; i < n; i++) {
    printf("%c", t[i]);
  }
  return 0;
}
