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.to_i
vs = gets.split

oc = Hash.new(0)
ec = Hash.new(0)
(0..n).each do |i|
  if i.odd?
    oc[vs[i]] += 1
  else
    ec[vs[i]] += 1
  end
end
ans = 0
oc = oc.sort { |(k1, v1),(k2,v2)| v2<=>v1 }
ec = ec.sort { |(k1, v1),(k2,v2)| v2<=>v1 }
ocmax = oc[0]
ecmax = ec[0]
if ocmax[0] == ecmax[0]
  if ocmax[1] == ecmax[1]
    if ec.dig(1,1).to_i > oc.dig(1,1).to_i
      ans += n - ocmax[1] - ec.dig(1,1).to_i
    else
      ans += n - ecmax[1] - oc.dig(1,1).to_i
    end
  elsif ocmax[1] > ecmax[1]
    ans += n - ocmax[1] - ec.dig(1,1).to_i
  else
    ans += n - ecmax[1] - oc.dig(1,1).to_i
  end
else
  ans += n - ocmax[1] - ecmax[1]
end
puts ans