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 Ruby (2.3.3) (judge verdict: Time Limit Exceeded)

total = gets
num_arr = gets.chomp!.split(' ')

count = 1

odd_arr = []
even_arr = []

num_arr.each do |num|
  if ((count % 2) == 1) then odd_arr << num
  else even_arr << num
  end
  count = count + 1
end

odd_flag_num = 0
odd_max_change_num = 0
odd_arr.each do |n|
  if ((odd_arr.length - odd_arr.count(n)) > odd_max_change_num) then
    odd_flag_num = n
    odd_max_change_num = odd_arr.length - odd_arr.count(n)
  end
end


even_flag_num = 0
even_max_change_num = 0
even_arr.each do |n|
  if ((even_arr.length - even_arr.count(n)) > even_max_change_num) then
    even_flag_num = n
    even_max_change_num = even_arr.length - even_arr.count(n)
  end
end

if odd_arr[0] != even_arr[0] then
  puts (odd_max_change_num + even_max_change_num)
else
  if odd_arr.length < even_arr.length then puts odd_arr.length
  else
    puts even_arr.length
  end
end