Problem Statement

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 1

4 3
3 3 -4 -2

Sample Output 1

-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 $\-6$.

Sample Input 2

10 40
5 4 3 2 -1 0 0 0 0 0

Sample Output 2

6

Sample Input 3

30 413
-170202098 -268409015 537203564 983211703 21608710 -443999067 -937727165 -97596546 -372334013 398994917 -972141167 798607104 -949068442 -959948616 37909651 0 886627544 -20098238 0 -948955241 0 -214720580 277222296 -18897162 834475626 0 -425610555 110117526 663621752 0

Sample Output 3

448283280358331064