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: Runtime Error)

#include <bits/stdc++.h>
using namespace std;
#define ARRAY_LENGTH(array) (sizeof(array) / sizeof(array[0]))
#define MAX(arr) *max_element(arr, arr + ARRAY_LENGTH(arr))
#define MAXID(arr) distance(arr,max_element(arr, arr + ARRAY_LENGTH(arr)))

int N;
int ev[10006], ov[10006];
int ob[10006]={0}, eb[10006]={0};
int ans, omost, emost, otmp, etmp;
int main(){
	cin >> N;

	for(int i=0;i<N;i++){
		if(i%2==0){
			cin >> ev[i];
			eb[ev[i]]++;
		}
		else {
			cin >> ov[i];
			ob[ov[i]]++;
		}
	}
	omost= MAXID(ob);
	emost= MAXID(eb);
	if (omost!=emost){
		ans = N-MAX(ob)-MAX(eb);
		cout << N-MAX(ob)-MAX(eb) << endl;
	}
	else{
		otmp = MAX(ob);
		etmp = MAX(eb);
		ob[omost]=0;eb[emost]=0;
		ans = min(N-MAX(ob)-etmp,N-MAX(eb)-otmp);
		cout << ans << endl;
	}
	return 0;
}