AT_abc471_f [ABC471F] Concat (maximize)

You are given $ N $ strings $ S_1,\ldots,S_N $ consisting of digits. Find the maximum possible value, when interpreted as a decimal integer (after removing extra leading zeros), of a string obtained by choosing exactly $ K $ of these strings and concatenating them in any order of your choice. Here, the value obtained by interpreting a string consisting entirely of the character `0` as a decimal integer after removing extra leading zeros is defined to be $ 0 $ .

The input is given from Standard Input in the following format: > $ N $ $ K $ $ S_1 $ $ \vdots $ $ S_N $

Output the answer.

### Sample Explanation 1 There are six strings obtained by choosing two of `123`, `45`, `6` and concatenating them: `12345`, `1236`, `45123`, `456`, `6123`, `645`. Among these, the maximum value when interpreted as a decimal integer is $ 45123 $ . ### Sample Explanation 3 The answer must be output without extra leading zeros. ### Constraints - $ 1 \leq K \leq N \leq 10^5 $ - $ S_i $ is a string of length between $ 1 $ and $ 10 $ (inclusive) consisting of digits. - $ N $ and $ K $ are integers.