CF219A.k-String

A string is called a $k$ -string if it can be represented as $k$ concatenated copies of some string. For example, the string "aabaabaabaab" is at the same time a 1-string, a 2-string and a 4-string, but it is not a 3-string, a 5-string, or a 6-string and so on. Obviously any string is a 1-string.

You are given a string $s$ , consisting of lowercase English letters and a positive integer $k$ . Your task is to reorder the letters in the string $s$ in such a way that the resulting string is a $k$ -string.

The first input line contains integer $k$ ( $1<=k<=1000$ ). The second line contains $s$ , all characters in $s$ are lowercase English letters. The string length $s$ satisfies the inequality $1<=|s|<=1000$ , where $|s|$ is the length of string $s$ .

Rearrange the letters in string $s$ in such a way that the result is a $k$ -string. Print the result on a single output line. If there are multiple solutions, print any of them.

If the solution doesn't exist, print "-1" (without quotes).