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 (2.4.0) (judge verdict: Accepted)

n = int(input())
ans = []
L = list(map(int,input().split()))
if len(list(filter(lambda x:x==L[0] ,L))) == len(L):
    print(n//2)
    quit()


import collections as col
L1 = L[::2]
L2 = L[1::2]
c1 = sorted(list(col.Counter(L1).items()),key=lambda x:x[1])[::-1]
c2 =sorted(list(col.Counter(L2).items()),key=lambda x:x[1])[::-1]

for i in range(3):
    for j in range(3):
        try:
            tmp1 = c1[i][0]
            tmp2 = c2[j][0]
            if tmp1 == tmp2 :
                continue
            a1 = n//2 - c1[i][1]
            a2 = n//2 - c2[j][1]
            ans.append(a1+a2)
        except:
            pass
print(min(ans))