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


$v_arr = explode(' ', $v);

fscanf(STDIN, "%d", $n);
$v_arr = explode(' ', trim(fgets(STDIN)));

$odd_arr = [];
$even_arr = [];
foreach ($v_arr as $i => $v) {
    if ($i % 2 === 0) {
        $even_arr[] = $v;
    } else {
        $odd_arr[] = $v;
    }
}

// Odd
$tmp_arr = [];
foreach ($odd_arr as $odd) {
    if (!isset($tmp_arr[$odd])) {
        $tmp_arr[$odd] = 1;
    } else {
        ++$tmp_arr[$odd];
    }
}
arsort($tmp_arr);


$tmp_arr2 = [];
foreach ($even_arr as $even) {
    if (!isset($tmp_arr2[$even])) {
        $tmp_arr2[$even] = 1;
    } else {
        ++$tmp_arr2[$even];
    }
}
arsort($tmp_arr2);


$odds = array_keys($tmp_arr);
$evens = array_keys($tmp_arr2);

if ($odds[0] != $evens[0]) {
    $odd_count = count($odd_arr) - $tmp_arr[$odds[0]];
    $even_count = count($even_arr) - $tmp_arr2[$evens[0]];

    echo $odd_count + $even_count;
} else {
    if ($tmp_arr[$odds[0]] > $tmp_arr2[$evens[0]]) {
        $odd_count = count($odd_arr) - $tmp_arr[$odds[0]];
        $even_count = count($even_arr) - $tmp_arr2[$evens[1]];

        echo $odd_count + $even_count;
    } elseif ($tmp_arr[$odds[0]] < $tmp_arr2[$evens[0]]) {
        $odd_count = count($odd_arr) - $tmp_arr[$odds[1]];
        $even_count = count($even_arr) - $tmp_arr2[$evens[0]];

        echo $odd_count + $even_count;
    } else {

        if ($tmp_arr[$odds[1]] > $tmp_arr2[$evens[1]]) {
            $odd_count = count($odd_arr) - $tmp_arr[$odds[1]];
            $even_count = count($even_arr) - $tmp_arr2[$evens[0]];

echo PHP_EOL;
echo $odd_count + $even_count;
        } else {
            $odd_count = count($odd_arr) - $tmp_arr[$odds[0]];
            $even_count = count($even_arr) - $tmp_arr2[$evens[1]];

            echo $odd_count + $even_count;
        }
    }
}