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<cstdio>
#include<cstdlib>
#include<fstream>
#include<cmath>
#include<string>
#include<cstring>
#include<algorithm>
using namespace std;

int n;
int a[200000],b[200000];

void init()
{
cin>>n;
n/=2;
for (int i=0; i<n; ++i)
{
    cin>>a[i]>>b[i];
}
}


int check(int a[200000])
{
    int flag[200000]={0};
    for (int i=0; i<n; ++i)
        flag[a[i]]++;
    int num=0,fre=0;
    for (int i=0; i<150000; ++i)
        if (flag[i]>fre)
            fre=flag[i];
    return n-fre;
}

void work()
{
    int sum=check(a)+check(b);
    cout<<sum<<endl;
}


int main()
{
    init();
    work();
    return 0;
}