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)

#include <iostream>
#include <vector>
#include <unordered_map>
#include <map>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <deque>
#include <cmath>
#include <stack>
#include <queue>
#include <string>
#include <iomanip>
#include <cstring>
#include <climits>
#include <cstdio>

#define nl '\n'

using namespace std;

long long n, a, x, t;

int main(){

    vector<long long> v;

    map<long long, long long> m;

    cin >> n;

    for(long long i = 0; i < n; i++){
        cin >> a;
        m[a]++;
        v.push_back(a);
    }

    if(n == 2){
        if(v[0] != v[1
        ]){
            cout << 0;
            return 0;
        } else {
            cout << 1;
            return 0;
        }
    } else {
        for(long long i = 0; i <= n-3; i++){
            if(v[i] == v[i+2]){
                continue;
            } else {
                x++;
            }
        }
    }

    for(long long i = 0; i < m.size(); i++){
        if(m[i] != 0){
            t++;
        }
    }

    if(t < 2){
        cout << x + (n/2);
        return 0;
    }

    cout << max(x, (abs(2-t)));
    return 0;








}
 
//g++ -std=c++14 comp.cpp -o c && c.exe
//g++ -std=c++14 comp.cpp -o c; ./c.exe
//g++ -std=c++14 comp.cpp && ./a.out


//Surely this is going to AC