CF263B.Squares

传统题 时间 2000 ms 内存 256 MiB 4 尝试 1 已通过 1 标签

Squares

Vasya has found a piece of paper with a coordinate system written on it. There are n distinct squares drawn in this coordinate system. Let's number the squares with integers from 1 to n. It turned out that points with coordinates (0, 0) and (a**i, a**i) are the opposite corners of the i-th square.

Vasya wants to find such integer point (with integer coordinates) of the plane, that belongs to exactly k drawn squares. We'll say that a point belongs to a square, if the point is located either inside the square, or on its boundary.

Help Vasya find a point that would meet the described limits.

Input

The first line contains two space-separated integers n, k (1 ≤ n, k ≤ 50). The second line contains space-separated integers a1, a2, ..., a**n (1 ≤ a**i ≤ 109).

It is guaranteed that all given squares are distinct.

Output

In a single line print two space-separated integers x and y (0 ≤ x, y ≤ 109) — the coordinates of the point that belongs to exactly k squares. If there are multiple answers, you are allowed to print any of them.

If there is no answer, print "-1" (without the quotes).

Samples

4 3
5 1 3 4
2 1
3 1
2 4 1
4 0
4 50
5 1 10 2
-1

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