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[] A = new int[100000+2];
		int[] B = new int[100000+2];
		
		int n = sc.nextInt();
		for (int i=1; i<=n; ++i){
			int x = sc.nextInt();
			if (i%2 == 1){
				A[x]++;
			} else {
				B[x]++;
			}
		}
		
		int mx1 = 0, mx2 = 0, valmx1=0, valmx2=0;
		for (int i=1; i<=100000; ++i){
			if (mx1 < A[i]){
				mx1 = A[i];
				valmx1 = A[i];
			}
			if (mx2 < B[i]){
				mx2 = B[i];
				valmx2 = B[i];
			}
		}
		if (valmx1 == valmx2){
			System.out.print( n/2 );
		} else {
			System.out.print( n/2 - mx1 + n/2 - mx2 );
		}
	}

}