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 <cmath>
#include<string>
using namespace std;
int main(void){
    
    int a;
    cin>>a;
    int retu[a];
    for(int i=0;i<a;i++){
        cin>>retu[i];
    }
    int ans=0;
    if(retu[0]==retu[1]){
        retu[1]++;
        ans++;
    }
    int a1=retu[0];
    int a2=retu[1];
    for(int i=0;i<a-2;i++){
        if(retu[i]!=retu[i+2]){
            if(retu[i]==a1){
                retu[i+2]=a1;
            }else if(retu[i]==a2){
                retu[i+2]=a2;
            }
            ans++;
        }
    }
    cout<<ans<<endl;
    
    return 0;
}