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 (2.7.1) (judge verdict: Accepted)

n=gets.to_i
s=gets.split.map &:to_i
h1=Hash.new(0);h2=Hash.new(0)
for i in 0...n
 i.even? ? h1[s[i]]+=1:h2[s[i]]+=1
end
ans1=h1.sort_by{|k,v|-v}.shift(2)
ans2=h2.sort_by{|k,v|-v}.shift(2)
ans1 << [0,0]
ans2 << [0,0]
if ans1[0][0]==ans2[0][0]
  puts n-([ans1[0][1]+ans1[1][1],ans2[0][1]+ans2[1][1]].max)
else
  puts n-ans1[0][1]-ans2[0][1]
end