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: Wrong Answer)

parseInt(x) = parse(Int, x)
parseMap(x::Array{SubString{String},1}) = map(parseInt, x)
function main()
    n=parseInt(readline())
    v=parseMap(split(readline()))
    cnt=Dict{Int,Int}()
    for i in v
        try
            cnt[i]+=1
        catch
            cnt[i]=1
        end
    end
    MAX=Tuple{Int,Int}[(0,0) for i in 1:2]
    for i in keys(cnt)
        if MAX[1][2]<=cnt[i]
            MAX[1],MAX[2]=(i,cnt[i]),MAX[1]
        end
    end
    cnt1,cnt2=0,0
    for i in 1:n
        if i%2==1
            if MAX[1][1]!=v[i]
                cnt1+=1
            end
            if MAX[2][1]!=v[i]
                cnt2+=1
            end
        else
            if MAX[2][1]!=v[i]
                cnt1+=1
            end
            if MAX[1][1]!=v[i]
                cnt2+=1
            end
        end
    end
    println(min(cnt1,cnt2))
end
main()