The largest product of numbers in a sequence

You are given a set of $n$ numbers. Your task is to find the maximum possible product that can be obtained by multiplying exactly $nmax$ numbers from this set.

Input

The input consists of two lines:

• The first line contains two space-separated integers, $n$ and $nmax$, where $4\le n\le 20$ and $3\le nmax<n$.

• The second line contains $n$ space-separated integers, each in the range $[-9,9]$.

Output

Print the maximum product that can be achieved by selecting exactly $nmax$ numbers from the given set.

Examples