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 Python (3.8.2) (judge verdict: Wrong Answer)

import collections
n = int(input())
v = [int(i) for i in input().split()]
kisu = []
gusu = []

kisu = v[::2]
gusu = v[1::2]

kisu_cnt = collections.Counter(kisu)
gusu_cnt = collections.Counter(gusu)

kisu_cnt = kisu_cnt.most_common(2)#引数にnを用意すると，出現回数の多い順にn子だけ呼び出せる
gusu_cnt = gusu_cnt.most_common(2)
kisu_most  = 0
gusu_most = 0
if kisu_cnt[0][0]!=gusu_cnt[0][0]:
    print(n-kisu_cnt[0][1]-gusu_cnt[0][1])
    exit()
else:
    if len(kisu_cnt)==len(gusu_cnt):
        print(n//2)
        exit()
    else:
        print(n-max(kisu_cnt[0][1]+gusu_cnt[1][1],kisu_cnt[1][1]+gusu_cnt[0][1]))