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 sc = new Scanner(System.in);
		int num = sc.nextInt();
		int counts[][] = new int[2][100010];
		for(int i = 0; i < num; i ++) {
			counts[i % 2][sc.nextInt()] ++;
		}
		int maxCount[][] = {{0, 0}, {0, 0}};
		int maxNumber[] = {0, 0};
		for(int i = 1; i < 100010; i ++) {
			for(int j = 0; j < 2; j ++) {
				if(counts[j][i] > maxCount[j][0]) {
					maxCount[j][0] = counts[j][i];
					maxNumber[j] = i;
				}else if(counts[j][i] > maxCount[j][1]) {
					maxCount[j][1] = counts[j][i];
				}
			}
		}
		int ans = num;
		if(maxNumber[0] == maxNumber[1]) {
			ans -= Math.max(maxCount[0][0] + maxCount[1][1], maxCount[0][1] + maxCount[1][0]);
		}else {
			ans -= maxCount[0][0] + maxCount[1][0];
		}
		System.out.println(ans);
	}
}