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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
public class Main{
    public static void main(String []args){
        Scanner x=new Scanner(System.in);
        int a=x.nextInt();
        int b[]=new int [a];
        for(int i=0;i<a;i++){
            b[i]=x.nextInt();
        }
        int qq=0;
        for(int i=0;i<a-1;i++){
            if(b[i]==b[i+1])
                qq=b[i];
        }
        if(qq==b[0]){
            System.out.println(a/2);
        }
        else{
            int count=0;
            for(int i=2;i<a-2;i++){
                if(b[i]!=b[i+2]&&b[i]!=b[i-2]){
                    count++;
                     b[i+2]=b[i];
                }
            }
            System.out.println(count);
        }
     }
}