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: Wrong Answer)

n = gets.chomp.to_i
vs = gets.chomp.split
k = 0
vs_odd = []
vs_even = []
n.times do
  if k.even?
    vs_odd << vs[k]
  else
    vs_even << vs[k]
  end
  k += 1
end
vs_odd.map!(&:to_i)
vs_even.map!(&:to_i)
vs_even.sort!
vs_odd.sort!
l = 0
m = 0
o = 0
((n / 2)-1).times do
  if vs_even[o] == vs_even[o+1]
    l += 1
    puts "same"
  else
    l = 0
  end
  if l >= m
    m = l
  end
  o += 1
end
l2 = 0
m2 = 0
o2 = 0
((n / 2)-1).times do
  if vs_odd[o2] == vs_odd[o2+1]
    l2 += 1
    puts "same"
  else
    l2 = 0
  end
  if l2 >= m2
    m2 = l2
  end
  o2 += 1
end

puts n - (2 + m + m2)