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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

    using System;
    using System.Text;
    using System.Collections.Generic;
    using static System.Math;
    using System.Linq;
    using static System.Array;
    
    namespace ConsoleApp2
    {
    class Program
    {
        static string S;
        static void Main(string[] args)
        {
            
            var N = long.Parse(Console.ReadLine());
            var V = Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();

            var dic1 = new Dictionary<long, long>();
            var dic2 = new Dictionary<long, long>();

            for (int i = 0; i < N; i++)
            {
                var now = V[i];
                if (i % 2 == 0)
                {
                    if (dic1.ContainsKey(now))
                    {
                        dic1[now]++;
                    }
                    else
                    {
                        dic1.Add(now,1);
                    }
                }
                else
                {
                    if (dic2.ContainsKey(now))
                    {
                        dic2[now]++;
                    }
                    else
                    {
                        dic2.Add(now, 1);
                    }
                }
            }
            dic2.Add(0,0);
            dic1.Add(0,0);
            var d1max  = -1L;
            var d1maxK  = -1L;
            var d1max2 = -1L;
            var d1max2K = -1L;
            foreach (var item in dic1)
            {
                if (item.Value > d1max)
                {
                    d1max2 = d1max;
                    d1max2K = d1maxK;
                    d1max = item.Value;
                    d1maxK = item.Key;
                }
                else if (item.Value > d1max2)
                {
                    d1max2 = item.Value;
                    d1max2K = item.Key;
                }
            }


            var d2max = -1L;
            var d2maxK = -1L;
            var d2max2 = -1L;
            var d2max2K = -1L;
            foreach (var item in dic2)
            {
                if (item.Value > d2max)
                {
                    d2max2 = d2max;
                    d2max2K = d2maxK;
                    d2max = item.Value;
                    d2maxK = item.Key;
                }
                else if (item.Value > d2max2)
                {
                    d2max2 = item.Value;
                    d2max2K = item.Key;
                }
            }

            if(d2maxK != d1maxK)
            {
                Console.WriteLine((N - d1max - d2max));
            }
            else
            {


                Console.WriteLine(Min((N - d1max2 - d2max), (N - d1max - d2max2)));
            }

            
        }
    }
}