Gru and minions are playing with numbers. Gru gives a list of numbers to a minion and asks him to tell the minimum possible last number of a non decreasing sequence of length L.
Input: Input consists of number of test cases T. Each test case contains size of array i.e N. Next line contains N space separated elements of array. Next line contains length of the non decreasing sequence i.e. L.
Output: You have to print the minimum possible last number of a sequence and if their is no non-decreasing sequence of length L, then print "-1" without the quotes.
Constraints: 1 <= T <= 100 | 1 <= N <= 106 | 1 <= a[i] <= 106 | 1 <= L <= N
In sample input, possible non-decreasing sequences of length L=3 are (9,11,12) , (7,11,12) , (2,5,11) , (2,4,11) , (2,5,12) , (2,4,12) , (2,11,12) , (5,11,12) , (4,11,12) and the minimum last number is 11 for the sequences (2,5,11) and (2,4,11). Hence, the answer is 11.
