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 Python (3.8.2) (judge verdict: Wrong Answer)

def readinput():
    n=int(input())
    v=list(map(int,input().split()))
    return n,v

def main(n,v):

    hist=[0]*(10**5+1)
    maxhist=0
    maxvalue=0
    for i in range(n):
        hist[v[i]]+=1
        if (maxhist<hist[v[i]]):
            maxhist=hist[v[i]]
            maxvalue=v[i]
    print('maxvalue: {}, maxhist: {}'.format(maxvalue, maxhist))

    secondhist=0
    for i in range(1,10**5+1):
        if i == maxvalue:
            continue
        secondhist=max(secondhist,hist[i])
    print('secondhist: {}'.format(secondhist))

    nsame=n//2
    nchange=0
    if maxhist>nsame:
        nchange+=maxhist-nsame
    elif maxhist<nsame:
        nchange+=nsame-maxhist
    nchange+=nsame-secondhist
    return nchange

def main2(n,v):
    eList=[]
    oList=[]
    for i in range(n):
        if i%2==0:
            eList.append(v[i])
        else:
            oList.append(v[i])
    hist=[0]*(10**5+1)
    for i in eList:
        hist[i]+=1
    emaxh=0
    emaxv=0
    for i in range(1,10**5+1):
        if emaxh<hist[i]:
            emaxh=hist[i]
            emaxv=i
    
    hist=[0]*(10**5+1)
    for i in oList:
        hist[i]+=1
    omaxh=0
    omaxv=0
    for i in range(1,10**5+1):
        if omaxh<hist[i]:
            omaxh=hist[i]
            omaxv=i
    if omaxv==emaxv:
        emaxv=(emaxv+1)%10**5
    
    nchange=0
    for i in range(n//2):
        if eList[i]!=emaxv:
            nchange+=1
        if oList[i]!=omaxv:
            nchange+=1
    return nchange


if __name__=='__main__':
    n,v=readinput()
    ans=main2(n,v)
    print(ans)