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 PyPy3 (7.3.0) (judge verdict: Wrong Answer)

#100 C - /\/\/\/
import collections
n = int(input())
A = list(map(int,input().split()))

A1 = A[::2]
A2 = A[1::2]
cnt1 = collections.Counter(A1)
cnt2 = collections.Counter(A2)

items1 = list(cnt1.items())
items2 = list(cnt2.items())

if items1[0][0] != items2[0][0]:
    ans = (len(A1) - items1[0][1]) + (len(A2) - items2[0][1])
else:
    if len(items1) == len(items2) == 1:
        ans = min(len(A1),len(A2))
    else:
        ans1 = (len(A1) - items1[0][1]) + (len(A2) - items2[1][1])
        ans2 = (len(A1) - items1[1][1]) + (len(A2) - items2[0][1])
        ans = min(ans1,ans2)
print(ans)