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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>

//#include<bits/stdc++.h>


using namespace std;



int main() {
	
	int n;
	cin >> n;
	vector<int>a, b;
	for (int i = 0; i < n; i++) {

		int t;
		cin >> t;
		if (i % 2)b.push_back(t);
		else a.push_back(t);
	}
	map<int, int>c, d;
	for (int i = 0; i < a.size(); i++)c[a[i]]++;
	for (int i = 0; i < b.size(); i++)d[b[i]]++;

	vector<pair<int, int>>x, y;
	for (int i = 0; i < a.size(); i++) {
		if (c[a[i]]) {
			x.push_back(make_pair(c[a[i]], a[i]));
			c[a[i]] = 0;
		}
	}

	for (int i = 0; i < b.size(); i++) {
		if (d[b[i]]) {
			y.push_back(make_pair(d[b[i]], b[i]));
			d[b[i]] = 0;
		}
	}
	//cout << x.size() << " " << y.size() << endl;
	sort(x.rbegin(), x.rend());
	sort(y.rbegin(), y.rend());
	//reverse(x.begin(), x.end());
	//reverse(y.begin(), y.end());
	int ans = n/2;
	if (x[0].second != y[0].second) {
		cout << n - x[0].first - y[0].first << endl;
		return 0;
	}
	if (x.size() == 1 && y.size() == 1) {
		cout << n / 2 << endl;
		return 0;
	}
	for (int i = 0; i < 2 || i < x.size(); i++) {
		for (int j = 0; j < 2 || j < y.size(); j++) {
			if (i==j)continue;
			ans = min(ans, n - x[i].first - y[j].first);
		}
	}
	
	cout << ans << endl;

	return 0;

}