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)

#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<bool> vb;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define in insert
#define FOR(i,a,b) for (int i = a; i < b; i++)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define speed ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
const int INF = 1e9 + 5;
int main(){
    int n;
    cin >> n;
    vi a(n);
    map<int, int> m1, m2;
    for(int i = 0; i < n; i++) {
        int x;
        cin >> x;
        if(i % 2 == 0) m1[x]++;
        else m2[x]++;
    }
    int mx1 = 0;
    int mx2 = 0;
    for(auto x : m1){
        mx1 = max(mx1, x.s);
    }
    for(auto x : m2){
        mx2 = max(mx2, x.s);
    }
    cout << n - mx1 - mx2; 
}