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

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).