A9111 | Banana

Piegirl is buying stickers for a project. Stickers come on sheets, and each sheet of stickers contains exactly $n$ stickers. Each sticker has exactly one character printed on it, so a sheet of stickers can be described by a string of length $n$ . Piegirl wants to create a string $s$ using stickers. She may buy as many sheets of stickers as she wants, and may specify any string of length $n$ for the sheets, but all the sheets must be identical, so the string is the same for all sheets. Once she attains the sheets of stickers, she will take some of the stickers from the sheets and arrange (in any order) them to form $s$ . Determine the minimum number of sheets she has to buy, and provide a string describing a possible sheet of stickers she should buy.

The first line contains string $s$ ( $1<=|s|<=1000$ ), consisting of lowercase English characters only. The second line contains an integer $n$ ( $1<=n<=1000$ ).

On the first line, print the minimum number of sheets Piegirl has to buy. On the second line, print a string consisting of $n$ lower case English characters. This string should describe a sheet of stickers that Piegirl can buy in order to minimize the number of sheets. If Piegirl cannot possibly form the string $s$ , print instead a single line with the number -1.