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.ArrayList;
import java.util.Collections;
import java.util.Scanner;


public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int n = Integer.parseInt(scanner.nextLine());
		ArrayList<Integer> ov = new ArrayList<Integer>();
		ArrayList<Integer> ev = new ArrayList<Integer>();
		for (int i = 0; i < n; i++) {
			if ((i + 1) % 2 != 0) {
				ov.add(Integer.parseInt(scanner.next()));
			} else {
				ev.add(Integer.parseInt(scanner.next()));
			}
		}
		Collections.sort(ov);
		int maxOddNum = 0;
		int index = 0;
		int i = 0;
		int repOddNum = 0;
		for (int num : ov) {
			if (ov.get(index) != num) {
				if ((i - index) > maxOddNum) {
					maxOddNum = i - index;
					repOddNum = ov.get(index);
				}
				index = i;
			}
			if ((i + 1) == ov.size()) {
				if (((i + 1) - index) > maxOddNum) {
					maxOddNum = (i + 1) - index;
					repOddNum = ov.get(index);
				}
			}
			i++;
		}

		Collections.sort(ev);
		int maxENum = 0;
		index = 0;
		i = 0;
		for (int num : ev) {
			if (ev.get(index) != num) {
				if (ev.get(index) != repOddNum) {
					if ((i - index) > maxENum) {
						maxENum = i - index;
					}
				}
				index = i;
			}
			if ((i + 1) == ov.size()) {
				if (ev.get(index) != repOddNum) {
					if (((i + 1) - index) > maxENum) {
						maxENum = (i + 1) - index;
					}
				}
			}
			i++;
		}


		System.out.println(n - (maxOddNum + maxENum));
	}

}