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.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.nextLine());
		String s = sc.nextLine();
		String[] spl = s.split(" ");
		int[] v = new int[n];
		for(int i = 0;i < n;i++){
			v[i] = Integer.parseInt(spl[i]);
		}
		sc.close();

		
		int[] diff = new int[n/2];
		
		for(int i = 0;i < n/2;i++){
			diff[i] = Math.abs(v[2*i] - v[2*i + 1]);
		}
		
		int num = 0;
		int cnt = 0;
		int results = n/2;	
		for(int i = 0;i < diff.length;i++){
			num = diff[i];
			for(int j = 0;j < diff.length;j++){
				if(diff[j] != num || diff[j] == 0){
					cnt++;
				}
			}
			if(cnt < results){
				results = cnt;
			}
			cnt = 0;
		}
		System.out.println(results);
	}
}