Xenny had a list of N strings of equal length. He wanted to sort them by the first M characters only. That means, while sorting the list of strings, he only wanted to consider the first M characters of each string.
Help Xenny to find out the Kth string in the list after he sorts them.
Note: Xenny wanted to perform stable sorting.
Stable sorting algorithms maintain the relative order of records with equal keys (i.e. values). That is, a sorting algorithm is stable if whenever there are two records R and S with the same key and with R appearing before S in the original list, R will appear before S in the sorted list.
Input
First line contains a single integer - T, which represents the number of testcases.
T testcases follow.
Each testcase is of the following format:
First line contains 3 space-separated integers - N, K and M.
N is the total number of strings Xenny has.
K is the index of the string in the list after sorting, which Xenny has to find.
M is the number of characters based on which sorting will be done by Xenny.
Then next N lines contain N strings ( each line will contain one string ) .
Output
For each testcase, print the Kth string in the sorted list in a new line.
Constraints
1 ≤ T ≤ 50
1 ≤ N ≤ 103
1 ≤ Max Length of each String ≤ 103
1 ≤ M ≤ Max Length
M ≤ Max Length of each String ≤ 103
After performing sorting by the first 3 characters, the order is:
1. aabaaa
2. abcdef
3. abcaaa
