• Find all subsequence of length K from an array whose final sum of subsequence is not divisible by 2.

Sample Input
5 3(K)
5 4 3 2 1

Sample Output
4

Explanation
{5, 4, 2} & {5, 3, 1} & {4, 3, 3} & {4, 2, 1}

How to solve this?