CF1029A.Many Equal Substrings

You are given a string $t$ consisting of $n$ lowercase Latin letters and an integer number $k$ .

Let's define a substring of some string $s$ with indices from $l$ to $r$ as $s[l \dots r]$ .

Your task is to construct such string $s$ of minimum possible length that there are exactly $k$ positions $i$ such that $s[i \dots i + n - 1] = t$ . In other words, your task is to construct such string $s$ of minimum possible length that there are exactly $k$ substrings of $s$ equal to $t$ .

It is guaranteed that the answer is always unique.

The first line of the input contains two integers $n$ and $k$ ( $1 \le n, k \le 50$ ) — the length of the string $t$ and the number of substrings.

The second line of the input contains the string $t$ consisting of exactly $n$ lowercase Latin letters.

Print such string $s$ of minimum possible length that there are exactly $k$ substrings of $s$ equal to $t$ .

It is guaranteed that the answer is always unique.