Given N different digits. You have to choose M digits from them to create all possible numbers in ascending order. For example, given 3 digits "4", "5", "6", and M = 2, the possible answers are "45", "46", "54", "56", "64", "65".
The first line contains a positive integer T (T <= 20), which indicates how many cases in the input. Each case starts with two positive integers N and M (1 <= M <= N <= 10), which denote the amount of the digits and the amount of digits of desired numbers. The next line contains exactly n different digits (0~9) separated by blanks.
For each case, first line outputs the case number. Then, output all the possible numbers in ascending order. (See the Sample Output)