We have N integers A_1, A_2, ..., A_N.
There are $\frac{N(N-1)}{2}$ ways to choose two of them and form a pair. If we compute the product of each of those pairs and sort the results in ascending order, what will be the K-th number in that list?

-----Constraints-----
- All values in input are integers.
- $2 \leq N \leq 2 \times 10^5$
- $1 \leq K \leq \frac{N(N-1)}{2}$
- -$10^9 \leq A_i \leq 10^9$\ $(1 \leq i \leq N)$

-----Input-----
Input is given from Standard Input in the following format:
N K
$A_1 A_2 \dots A_N$

-----Output-----
Print the answer.

-----Sample Input-----
4 3
3 3 -4 -2

-----Sample Output-----
-6

There are six ways to form a pair. The products of those pairs are 9, -12, -6, -12, -6, 8.
Sorting those numbers in ascending order, we have -12, -12, -6, -6, 8, 9. The third number in this list is -6.

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