题目描述
Given are $N integers A_1,\ldots,A_N$.
We will choose exactly K of these elements. Find the maximum possible product of the chosen elements.
Then, print the maximum product modulo (10^9+7), using an integer between 0 and 10^9+6 (inclusive).
Constraints
- $1 \leq K \leq N \leq 2\times 10^5$
- $|A_i| \leq 10^9$
Input
Input is given from Standard Input in the following format:
N K
$A_1 \ldots A_N$
Output
Print the maximum product modulo (10^9+7), using an integer between 0 and 10^9+6 (inclusive).
Examples
Input
4 2
1 2 -3 -4
Output
12
Input
4 3
-1 -2 -3 -4
Output
1000000001
Input
2 1
-1 1000000000
Output
1000000000
Input
10 10
1000000000 100000000 10000000 1000000 100000 10000 1000 100 10 1
Output
999983200
输入格式
见题面
输出格式
见题面
样例输入
4 2
1 2 -3 -4
样例输出
12