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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

var lines = [];
var readline = require('readline');

var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
});

rl.on('line', function (x) {
    lines.push(x);
});

rl.on('close', function () {
    var N = lines.shift(); N = Number(N);
    var v = Array(N);
    var counter_g = Array(N).fill(0); var max_g = -1;
    var counter_k = Array(N).fill(0); var max_k = -1;
    var result = 0;

    var tmp = lines[0].split(" ");
    for (var i = 0; i < N; i++) {
        v[i] = Number(tmp[i]);
        i % 2 === 0 ? counter_g[i]++ : counter_k[i]++;
    }

    var g = -1; var k = -1;
    for (var i = 0; i < N; i++) { if (counter_g[i] > max_g) { max_g = counter_g[i]; g = i; } }
    for (var i = 0; i < N; i++) { if (counter_k[i] > max_k && v[i] !== v[g]) { max_k = counter_k[i]; k = i; } }

    if (k === -1) { v[k] = -1; }

    console.log(v[g],v[k])
    for (var i = 0; i < N; i++) {
        if (i % 2 === 0 && v[i] !== v[g]) { result++; }
        if (i % 2 !== 0 && v[i] !== v[k]) { result++; }
    }
    console.log(result);
});