Find an element

Array of n integers is given. Find its k-th element in decreasing order.

Input

First line contains the number of elements n (1 ≤ n ≤ 10^5) in array, and integer k(1 ≤ k ≤ 10^5). Second line contains n integers, not greater than 10^9 by absolute value.

Output

Print the k-th element of array sorted in decreasing order, or -1 if such element does not exist.

Examples