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 PyPy3 (2.4.0) (judge verdict: Wrong Answer)

n=int(input())
v=list(map(int,input().split()))
from collections import defaultdict
a=defaultdict(int)
b=defaultdict(int)
for i in range(n):
    if i%2==0:
        a[v[i]]+=1
    else:
        b[v[i]]+=1
a=dict(sorted(a.items(), key=lambda x:x[1], reverse=True))
b=dict(sorted(b.items(), key=lambda x:x[1], reverse=True))
print(a,b)
ans=float('inf')
akeys=list(a.keys())
bkeys=list(b.keys())
if akeys[0]==bkeys[0]:
    if len(akeys)==1 and len(bkeys)==1:
        ans=n//2
    else:
        if len(akeys)>1:
            x=sum(a.values())-a[akeys[1]]+sum(b.values())-b[bkeys[0]]
            ans=min(x,ans)
        if len(bkeys)>1:
            x=sum(a.values())-a[akeys[0]]+sum(b.values())-b[bkeys[1]]
            ans=min(x,ans)
else:
    ans=sum(a.values())-a[akeys[0]]+sum(b.values())-b[bkeys[0]]
print(ans)