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: Wrong Answer)


N = int(input())
seq = list(map(int, input().rstrip().split(' ')))

odd = [0] * int(1e5 + 1)
even = [0] * int(1e5 + 1)

for i in range(0, N, 2):
    even[seq[i]] += 1
    
for i in range(1, N, 2):
    odd[seq[i]] += 1

type_number = 0
for i in range(0, int(1e5 + 1)):
    if odd[i] + even[i] > 0:
        type_number += 1

max_even = max(even)
max_odd = max(odd)

count = 0
count += N // 2 - max_even
count += N // 2 - max_odd

if type_number == 1:
    print(N // 2)
else:
    print(count)