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 Lua (5.3.2) (judge verdict: Wrong Answer)

n=io.read("*n","*l")
v={}
for i=1,n do
    x=io.read("*n")
    if i%2==1 then
        if not v[x] then
            v[x]={1,0}
        else
            v[x][1]=v[x][1]+1
        end
    else
        if not v[x] then
            v[x]={0,1}
        else
            v[x][2]=v[x][2]+1
        end
    end
end

omax={0,0}
emax={0,0}
omax2={0,0}
emax2={0,0}
for k,_ in pairs(v) do
    omax={math.max(omax[1],v[k][1]),k}
    emax={math.max(emax[1],v[k][2]),k}
end
for k,_ in pairs(v) do
    if k~=omax[2] then
        omax2={math.max(omax2[1],v[k][1]),k}
    elseif k~=emax[2] then
        emax2={math.max(emax2[1],v[k][2]),k}
    end
end

if omax[2]==emax[2] then
    print(n-math.max(omax2[1]+emax[1],omax[1]+emax2[1]))
else
    print(n-omax[1]-emax[1])
end