This task will exclusively concentrate only on the arrays where all elements equal 1 and/or 2. Array a is k -period if its length is divisible by k and there is such array b of length k , that a is represented by array b written exactly times consecutively. In other words, array a is k -periodic, if it has period of length k . For example, any array is n -periodic, where n is the array length. Array 2, 1, 2, 1, 2, 1 is at the same time 2-periodic and 6-periodic and array 1, 2, 1, 1, 2, 1, 1, 2, 1 is at the same time 3-periodic and 9-periodic. For the given array a , consisting only of numbers one and two, find the minimum number of elements to change to make the array k -periodic. If the array already is k -periodic, then the required value equals 0 . The first line of the input contains a pair of integers n , k ( 1 ≤ k ≤ n ≤ 100) , where n is the length of the array and the value n is divisible by k . The second line contains the sequence of elements of the given array a 1 , a 2 , ..., a n ( 1 ≤ a i ≤ 2 ), a i is the i -th element of the array. Print the minimum number of array elements we need to change to make the array k -periodic. If the array already is k -periodic, then print 0 . In the first sample it is enough to change the fourth element from 2 to 1 , then the array changes to 2, 1, 2, 1, 2, 1 . In the second sample, the given array already is 4-periodic. In the third sample it is enough to replace each occurrence of number two by number one. In this case the array will look as 1, 1, 1, 1, 1, 1, 1, 1, 1 — this array is simultaneously 1-, 3- and 9-periodic.