Given a non-negative number n and a value k. Find the k-th smallest number that can be formed using the digits of the given number n. It is guaranteed that the k-th smallest number can be formed. Note that the number could be very large and may not even fit into long long int.

Input:

The first line of input contains an integer T denoting the number of test cases. Then T test cases follow. The first line of each test case contains the integer n.

The second line of each test case contains the integer k. 

Output:

Print the k-th smallest number that can be formed using the digits of the number n for each test case in a new line. 

Constraints:

1<= T <=100

1<= N <=10¹⁰⁰⁰

1<= K <=10

Example:
Input:
2
1234
2
36012679802
5
Output:
1243
10022366897

** For More Input/Output Examples Use 'Expected Output' option **