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.*;
import java.util.Map.*;

class Main{
	static Scanner s=new Scanner(System.in);

	public static void main(String[] $){
		HashMap<Integer,Integer> o=new HashMap<>(),e=new HashMap<>();
		o.put(0,0);
		e.put(0,0);
		int n=s.nextInt();

		for(int i=0;i<n;++i)
			(i%2==0?e:o).merge(s.nextInt(),1,Integer::sum);

		Comparator<Entry<Integer,Integer>> c=Entry.comparingByValue();
		Entry<Integer,Integer> O=o.entrySet().stream().max(c).get();
		Entry<Integer,Integer> E=e.entrySet().stream().max(c).get();
		o.remove(O.getKey());
		e.remove(E.getKey());
		Entry<Integer,Integer> O2=o.entrySet().stream().max(c).get();
		Entry<Integer,Integer> E2=e.entrySet().stream().max(c).get();

		n-=O.getKey().equals(E.getKey())
				?O.getValue()+E.getValue()
				:Math.max(
					O.getValue()+E2.getValue(),
					E.getValue()+O2.getValue());
		System.out.println(n);
	}
}