I just find this problem but couldn't think of a solution ??can anyone will help me??

given N and K (2 <= N,K <= 8) and an array consisting of N distinct elements; in one move you can pick a block of K elements in the array and reverse the order, for example: if N = 5 and K = 3 and the array is [4 5 1 2 3], in one move you can make the array [1 5 4 2 3] or [4 2 1 5 3] or [4 5 3 2 1]. how many minimum number of moves is required to make the array sorted in ascending order?, if impossible, print -1.