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: Accepted)

n = int(input())
V = list(map(int,input().split()))
A = []
B = []
for i in range(n):
    if i%2==0:
        A.append(V[i])
    else:
        B.append(V[i])
from collections import Counter
NA = len(A)
NB = len(B)
Ac = dict(Counter(A))
Bc = dict(Counter(B))
Am = max(Ac.values())
Ak = max(Ac, key=Ac.get)
Bm = max(Bc.values())
Bk = max(Bc, key=Bc.get)
if len(Ac.keys())==1 and len(Bc.keys())==1 and A[0]==B[0]:
    print(NB)
else:
    if Ak!=Bk:
        print(NA-Am+NB-Bm)
    else:
        Ac[Ak] = 0
        Bc[Bk] = 0
        Am2 = max(Ac.values())
        Ak2 = max(Ac, key=Ac.get)
        Bm2 = max(Bc.values())
        Bk2 = max(Bc, key=Bc.get)
        print(min(NA-Am2+NB-Bm,NA-Am+NB-Bm2))