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)

from collections import Counter
n,*v = map(int,open(0).read().split())
v1 = Counter(v[::2])
v2 = Counter(v[1::2])
v1 = sorted([(i,v1[i]) for i in v1.keys()],key =lambda x:x[1],reverse=True)
v2 = sorted([(i,v2[i]) for i in v2.keys()],key =lambda x:x[1],reverse=True)
print(v1,v2)
if len(v1) == 1:
  if len(v2) == 1:
    if v1[0][0] != v2[0][0]:
      print(0)
    else:
      print(n//2)
  else:
    if v1[0][0] != v2[0][0]:
      print(n//2-v2[0][1])
    else:
      print(n//2-v2[1][1])
else:
  if len(v2) == 1:
    if v1[0][0] != v2[0][0]:
      print(n//2-v1[0][1])
    else:
      print(n//2-v1[1][1])
  else:
    if v1[0][0] != v2[0][0]:
      print(n-v1[0][1]-v2[0][1])
    else:
      print(min(n-v1[0][1]-v2[1][1],n-v1[1][1]-v2[0][1]))