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())
v_list = list(map(int,input().split()))
odd = v_list[0::2]
even = v_list[1::2]
import collections
c = collections.Counter(odd)
c = sorted(c.items(),reverse = True)
c.append((0,0))
c_max = c[0][1]
c_max_num = c[0][0]

d = collections.Counter(even)
d = sorted(d.items(),reverse = True)
d_max = d[0][1]
d_max_num = d[0][0]
d.append((0,0))

if d_max_num != c_max_num:
  print(len(v_list) - c_max - d_max)
elif c_max > d_max:
  print(len(v_list) - c_max - d[1][1])
else:
  print(len(v_list) - d_max - c[1][1])