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.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = Integer.parseInt(sc.nextLine());
        List<Integer> list = new ArrayList<>();

        for (int i=0; i<n; i++){
            list.add(Integer.parseInt(sc.next()));
        }

        int listSize = list.size();
        int errCnt = 0;

        for (int i=0; i<listSize-2; i++){
            if (!list.get(i).equals(list.get(i + 2))){
                errCnt++;
                list.set(i+2, list.get(i));
            }
            System.out.println(list);
        }

        if (checkListNum(list)){
            errCnt = listSize / 2;
        }

        System.out.println(errCnt);

    }

    private static boolean checkListNum(List<Integer> list){
        for (int i=0; i<list.size() - 1; i++){
            if (!(list.get(i).equals(list.get(i+1)))){
                return false;
            }
        }
        return true;
    }

}