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;

class Main{
	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		int N = scanner.nextInt();
		int[] data1 = new int[N];
		int[] data2 = new int[N];
		int[] counter1 = new int[1000000];
		int[] counter2 = new int[1000000];
		int ans = 0;

		int j = 0;
		for(int i = 0;i < N;i++){			//データ入力
			if(i%2 == 0){
				data1[i] = scanner.nextInt();
				counter1[data1[i]]++;
			}else{
				data2[j] = scanner.nextInt();
				counter2[data2[j]]++;
				j++;
			}
		}
		int max1 = 0;				//最頻数を発見
		int submax1 = 0;
		int c1 = 0;
		for(int i = 0;i < 1000000;i++){
			if(c1 <= counter1[i]){
				c1 = counter1[i];
				submax1 = max1;
				max1 = i;
			}
		}

		int max2 = 0;				//最頻数を発見
		int submax2 = 0;
		int c2 = 0;
		for(int i = 0;i < 1000000;i++){
			if(c2 <= counter2[i]){
				c2 = counter2[i];
				submax2 = max2;
				max2 = i;
			}
		}

		

		Arrays.sort(counter1);
		Arrays.sort(counter2);


		int k1 = 0;
		int k2 = 0;
		for(int i = counter1.length-2;i >= 0;i--){

			if(counter1[i] ==  0){
				break;
			}else{
				k1 += counter1[i];
			}
		}

		for(int i = counter2.length-2;i >= 0;i--){

			if(counter2[i] ==  0){
				break;
			}else{
				k2 += counter2[i];
			}
		}


		if(max1 == max2 ){
			if(k1 <= k2){
				for(int i = counter2.length-1;i >= 0;i--){

					if(counter2[i] ==  0){
						break;
					}else if(i == counter2.length-2){

					}else{
						k2 += counter2[i];
					}
				}
			}else{
				for(int i = counter1.length-1;i >= 0;i--){

					if(counter1[i] ==  0){
						break;
					}else if(i == counter1.length-2){

					}else{
						k1 += counter1[i];
					}
				}
			}
			System.out.println(k1+k2);

		}else{
			System.out.println(k1 + k2);

		}










	}
}