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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace SummerVacation
{
    class Program
    {
        static void Main(string[] args)
        {
            //List<List<int>> vs = new List<List<int>>() { new List<int> { 0, 10 }, new List<int> { 0, 5 } };

            //var num= vs.Where(g => g[0] == 0 && g[1] == g.Max()).Select(g => g.IndexOf(g.Max())).ToArray();

            //Console.WriteLine(num[0]);
            ////vs.RemoveAt(Convert.ToInt32(num));
            ////foreach (List<int> vs1 in vs)
            ////{
            ////    Console.WriteLine(string.Join("", vs1));

            ////}
            //Console.WriteLine("Hello World!");



            Console.ReadLine();
            string[] tmpstr=Regex.Split(Console.ReadLine(), @"\s+");
            int[] sep1_list = new int[] { 0, 0 };
            int[] sep2_list = new int[] { 0, 0 };

            string sep1 = tmpstr[0];
            string sep2 = tmpstr[1];
            for (int i = 0; i < tmpstr.Length; i += 2)
            {
                if (sep1 == tmpstr[i])
                {
                    sep1_list[0] += 1;
                }
                else
                {
                    sep1_list[1] += 1;
                }
                if (sep2 == tmpstr[i + 1])
                {
                    sep2_list[0] += 1;
                }
                else
                {
                    sep2_list[1] += 1;
                }
            }

            int tmpnum = sep1_list.Min() + sep2_list.Min();
            if (tmpnum == 0 && sep1 == sep2)
            {
                Console.WriteLine(sep1.Length);
            }
            else
            {
                Console.WriteLine(tmpnum);
            }

        }
    }
}