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: Runtime Error)

n=int(input())
V=list(map(int,input().split()))
E=Counter(V[::2]).most_common()
O=Counter(V[1::2]).most_common()

E1=E[0][1]
O1=O[0][1]
if E[0][0]==O[0][0]:
  print(n//2)
elif E1==O1==n//2:
  print(0)
else:
  E2=E[1][1] if len(E)>1 else 0
  O2=O[1][1] if len(O)>1 else 0
  if E2!=0 and O2!=0:
    print(min(n//2-E2+n//2-O1,n//2-E1+n//2-O2))
  else:
    print(min(n//2-E2+n//2-O1,n//2-E1+n//2-O2))