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 (3.4.3) (judge verdict: Accepted)

n = int(input())
v = list(map(int, input().split()))


even = [0] * (10 ** 5)
odd = [0] * (10 ** 5)

for i in range(0, n, 2):
    even[v[i] - 1] += 1

for i in range(1, n, 2):
    odd[v[i] - 1] += 1

even_max = max(even)
odd_max = max(odd)

even_max_i = even.index(even_max)
odd_max_i = odd.index(odd_max)

if even_max_i == odd_max_i:
    even[even_max_i] = 0
    odd[odd_max_i] = 0

    even_max_2 = max(even)
    odd_max_2 = max(odd)

    ans = n - max(even_max + odd_max_2, even_max_2 + odd_max)
else:
    ans = n - (even_max + odd_max)

print(ans)