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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <string>
#include <sstream>
using namespace std;

int main() {
	int n,count,check; 
    cin >> n;
  	int v[n];
    for (int i = 0; i < n; ++i) cin >> v[n];
    count = 0;
  	check = 0;
  	//cout << v[1] << endl;
  	for (int i = 0; i < n/2; ++i) {
      if(v[0] != v[2*i]){
        count +=1;
      }
      if(v[1] != v[2*i+1]){
        count +=1;
      }
     
    }
  	for (int i = 0; i < n-1; ++i){
		if(v[i] != v[i+1]){
          check +=1;
        }
    }
  	if(check == 0 ){
      count+=2;
    }
    cout << count-1 << endl;
}