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 {
    static class Counter implements Comparable<Counter> {
        int num = 0;
        int cnt = 0;

        Counter(int num) {
            this.num = num;
            cnt = 1;
        }

        public int compareTo(Counter o) {
            return o.cnt - cnt;
        }
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        List<Counter> counter1 = new ArrayList<>();
        List<Counter> counter2 = new ArrayList<>();

        for (int i = 0; i < n; i++) {
            int v = sc.nextInt();

            boolean isAdd = false;
            if (i % 2 == 0) {
                for (int j = 0; j < counter1.size(); j++) {
                    if (counter1.get(j).num == v) {
                        isAdd = true;
                        counter1.get(j).cnt++;
                    }
                }

                if (!isAdd) {
                    counter1.add(new Counter(v));
                }
            } else {
                for (int j = 0; j < counter2.size(); j++) {
                    if (counter2.get(j).num == v) {
                        isAdd = true;
                        counter2.get(j).cnt++;
                    }
                }

                if (!isAdd) {
                    counter2.add(new Counter(v));
                }
            }
        }

        Collections.sort(counter1);
        Collections.sort(counter2);

        int totalCnt1 = counter1.get(0).cnt;
        int totalNum1 = counter1.get(0).num;
        int totalCnt2 = counter2.get(0).cnt;
        int totalNum2 = counter2.get(0).num;
        for (int i = 1; i < counter2.size(); i++) {
            if (totalNum1 != totalNum2)
                break;
            if (counter1.get(i).num > counter2.get(i).num) {
                totalNum1 = counter1.get(i).num;
                totalCnt1 = counter1.get(i).cnt;
            } else {
                totalCnt2 = counter2.get(i).cnt;
            }
        }

        if (totalNum1 == totalNum2) {
            if (totalCnt1 > totalCnt2)
                totalCnt2 = 0;
            else
                totalCnt1 = 0;
        }

        System.out.println(n - (totalCnt1 + totalCnt2));
    }
}