A string $S$ of length $N$ is given.

You need to construct a string $T$ of length $M$. The number of times $S$ appears as a substring in $T$ must be maximized. The appearances of the substring may overlap.

For example, if $S=$dada and $T=$dadadadas, $S$ appears in $T$ a total of $3$ times, each starting from the $1$st, $3$rd, and $5$th letter of $T$.

The input is given in the following format.

$N\ M$ $S$

Print the answer in the following format.

$T$

If there are multiple strings that satisfy the condition, you may print any of them.

• $1 \le N \le 7\ 000$.
• $1 \le M \le 7\ 000$.
• $S$ consists only of lowercase English letters.
• The output string $T$ must also consist only of lowercase English letters.

$S_i$ denotes the $i$-th character of the string $S$. For example, if $S=$abcac, then $S_2=$b.