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: Accepted)

<?php
fscanf(STDIN, "%d", $n);
$v = explode(" ", trim(fgets(STDIN)));
$e = $o = [PHP_INT_MAX => 0];
foreach ($v as $k => $x) {
    if ($k % 2 === 0) {
        isset($e[$x]) ? $e[$x]++ : $e[$x] = 1;
    } else {
        isset($o[$x]) ? $o[$x]++ : $o[$x] = 1;
    }
}
arsort($e);
arsort($o);
// var_dump($e);
// var_dump($o);
$e_key = array_keys($e);
$e_val = array_values($e);
$o_key = array_keys($o);
$o_val = array_values($o);
if ($e_key[0] === $o_key[0]) {
    echo $n - max($e_val[0] + $o_val[1], $e_val[1] + $o_val[0]);
} else {
    echo $n - $e_val[0] - $o_val[0];
}