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.Arrays;
import java.util.Scanner;

public class Main {
	Scanner sc = new Scanner(System.in);
	void doIt() {
		int n = sc.nextInt();
		int v1[] = new int[n / 2];
		int v2[] = new int[n / 2];
		for(int i = 0; i < n / 2; i++) {
			v1[i] = sc.nextInt();
			v2[i] = sc.nextInt();
		}
		int m1 = 0, m2 = 0;
		int mm1 = 0, mm2 = 0;
		int cnt1[] = new int[100001];
		int cnt2[] = new int[100001];
		Arrays.fill(cnt1, 0);
		Arrays.fill(cnt2, 0);
		for(int i = 0; i < n / 2; i++) {
			cnt1[v1[i]]++;
			if(cnt1[m1] < cnt1[v1[i]]) m1 = v1[i];
			if(cnt1[mm1] < cnt1[v1[i]] && cnt1[v1[i]] < cnt1[m1])
				mm1 = v1[i];
			cnt2[v2[i]]++;
			if(cnt2[m2] < cnt2[v2[i]]) m2 = v2[i];
			if(cnt2[mm2] < cnt2[v2[i]] && cnt2[v2[i]] < cnt2[m2]) 
				mm2 = v2[i];

		}
		if(m1 == m2) {
			if(m1 <= m2)m2 = mm2;
			else m1 = mm2;
		}
		int cnt = n - cnt1[m1] - cnt2[m2];
		//System.out.println(m1 +" "+ m2);
		System.out.println(cnt);
	}
	Main(){doIt();}
	public static void main(String[] args) {
		new Main();
	}

}