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 v;
		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++) {
			v = sc.nextInt();
			cnt1[v]++;
			if(cnt1[m1] < cnt1[v]) m1 = v;
			else if(cnt1[mm1] < cnt1[v] && v != m1) mm1 = v;
			v = sc.nextInt();
			cnt2[v]++;
			if(cnt2[m2] < cnt2[v]) m2 = v;
			else if(cnt2[mm2] < cnt2[v] && v != m2) mm2 = v;
		}
		//System.out.println(m1 +" "+ m2 + " " +mm1 +" " +mm2);
		int min;
		if(m1 == m2) {
			min = cnt1[m1] + cnt2[mm2];
			if(cnt2[m2] + cnt1[mm1] > min) 
				min = cnt2[m2] + cnt1[mm1];
		}
		else min = cnt1[m1] + cnt2[m2];
		System.out.println(n - min);
	}
	Main(){doIt();}
	public static void main(String[] args) {
		new Main();
	}

}