Problem:
Score : 300 points

Problem Statement

A sequence a_1,a_2,... ,a_n is said to be /\/\/\/ when the following conditions are satisfied:

For each i = 1,2,..., n-2, a_i = a_{i+2}.

Exactly two different numbers appear in the sequence.

You are given a sequence v_1,v_2,...,v_n whose length is even.
We would like to make this sequence /\/\/\/ by replacing some of its elements.
Find the minimum number of elements that needs to be replaced.

Constraints

2 \leq n \leq 10^5

n is even.

1 \leq v_i \leq 10^5

v_i is an integer.

Input

Input is given from Standard Input in the following format:

n
v_1 v_2 ... v_n

Output

Print the minimum number of elements that needs to be replaced.

Sample Input 1

4
3 1 3 2

Sample Output 1

1

The sequence 3,1,3,2 is not /\/\/\/, but we can make it /\/\/\/ by replacing one of its elements: for example, replace the fourth element to make it 3,1,3,1.

Sample Input 2

6
105 119 105 119 105 119

Sample Output 2

0

The sequence 105,119,105,119,105,119 is /\/\/\/.

Sample Input 3

4
1 1 1 1

Sample Output 3

2

The elements of the sequence 1,1,1,1 are all the same, so it is not /\/\/\/.

Solution in PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
fscanf(STDIN, '%d', $cnt);
$nums = explode(' ', trim(fgets(STDIN)));
$ans = 0;
$a = max($nums);
$b = min($nums);
if ($a == $b) {
    echo ($cnt / 2)."\n";
    exit;
}
$now = $nums[0] == $a ? $a : $b;
for ($i=0; $i < $cnt; $i++) { 
    if ($nums[$i] != $a && $nums[$i] != $b) {
        switch ($now) {
            case $a:
                $nums[$i] = $b;
                $now = $b;
                $ans++;
                break;
            case $b:
                $nums[$i] = $a;
                $now = $a;
                $ans++;
                break;            
            default:
                break;
        }
    }
}
echo $ans."\n";