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 Julia (0.5.0) (judge verdict: Accepted)

parseInt(x) = parse(Int, x)

function main()
	n = readline() |> parseInt
	v = map(parseInt, split(readline()))
	od = Dict{Int,Int}()
	ed = Dict{Int,Int}()
	for i in 1:2:n
		if haskey(od,v[i])
			od[v[i]] += 1
		else
			od[v[i]] = 1
		end
	end
	for i in 2:2:n
		if haskey(ed,v[i])
			ed[v[i]] += 1
		else
			ed[v[i]] = 1
		end
	end
	co = sort(collect(od), by=x->x[2], rev=true)
	ce = sort(collect(ed), by=x->x[2], rev=true)
	if co[1][1] == ce[1][1]
		if length(ce) == 1 && length(co) == 1
			print(n-co[1][2])
		elseif length(ce) == 1
				print(min(n-co[1][2],n-ce[1][2]-co[2][2]))
		elseif length(co) == 1
			print(min(n-ce[1][2],n-co[1][2]-ce[2][2]))
		else
			print(min(n-co[1][2]-ce[2][2],n-co[2][2]-ce[1][2]))
		end
	else
		print(n-co[1][2]-ce[1][2])
	end
end

main()