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: Accepted)

n = int(input())
v = list(map(int, input().split()))
odd = dict()
even = dict()
odd[-1] = 0
even[-1] = 0

for i in range(n):
    if (i + 1) % 2 == 1:
        if v[i] not in odd:
            odd[v[i]] = 1
        else:
            odd[v[i]] += 1
    else:
        if v[i] not in even:
            even[v[i]] = 1
        else:
            even[v[i]] += 1

odd_values = sorted(list(odd.values()), reverse=True)
for key, val in odd.items():
    if val == odd_values[0]:
        odd_1 = key
    elif val == odd_values[1]:
        odd_2 = key

even_values = sorted(list(even.values()), reverse=True)
for key, val in even.items():
    if val == even_values[0]:
        even_1 = key
    elif val == even_values[1]:
        even_2 = key

if odd_1 != even_1:
    res = n - odd_values[0] - even_values[0]
else:
    res = min(n - odd_values[0] - even_values[1], 
              n - odd_values[1] - even_values[0])
print(res)
# print(odd)
# print(even)