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 (3.4.3) (judge verdict: Accepted)

n=int(input())
v=list(map(int,input().split()))

l=[v[i] for i in range(n) if i%2==0]
r=[v[i] for i in range(n) if i%2]

l.sort()
r.sort()

count=1
countl1=0
countl2=0

for i in range(1,len(l)):
    if l[i]==l[i-1]: count+=1
    else:
        if count>=countl1:
            countl1,countl2=count,countl1
            charl=l[i-1]
        elif count>countl2:
            countl2=count
        count=1
        
if count>=countl1:
    countl1,countl2=count,countl1
    charl=l[-1]
elif count>countl2:
    countl2=count 


count=1
countr1=0
countr2=0

for i in range(1,len(r)):
    if r[i]==r[i-1]: count+=1
    else:
        if count>=countr1:
            countr1,countr2=count,countr1
            charr=r[i-1]
        elif count>countr2:
            countr2=count
        count=1

if count>=countr1:
    countr1,countr2=count,countr1
    charr=r[-1]
elif count>countr2:
    countr2=count 
        
if charl==charr:
    print(n-max(countl1+countr2,countl2+countr1))
else: print(n-countl1-countr1)