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 $0$.

Input

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.

Output

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.

Note

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.