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.*;

class Main{
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] k = new int[100001];
		int[] g = new int[100001];
		int kmax = 0;
		int gmax = 0;
		int kid = 0;
		int gid = 0;
		for(int i = 1; i <= n; i++){
			int v = sc.nextInt();
			if(i%2 == 1){
				k[v]++;
				if(k[v] > kmax){
					kid = v;
					kmax = k[v];
				}
			}else{
				g[v]++;
				if(g[v] > gmax){
					gid = v;
					gmax = g[v];
				}
			}
		}
		if(gmax==n/2&&kmax==n/2&&kid==gid){
			System.out.print(n/2);
		}else{
			int ans = 0;
			Arrays.sort(g);
			Arrays.sort(k);
			for(int i = 99999; i >= 0; i--){
				if(k[i] != 0){
					ans += k[i];
				}else{
					break;
				}
			}
			for(int i = 99999; i >= 0; i--){
				if(g[i] != 0){
					ans += g[i];
				}else{
					break;
				}
			}
			System.out.print(ans);
		}
	}
}