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: Wrong Answer)

N = int(input())
prg = list(map(int,input().split()))

from collections import Counter

def prg_divide(s):
    arr = []
    for i in range(s,N,2):
        arr.append(prg[i])
        
    counter = Counter(arr)
    counter = sorted(counter.items(),key=lambda x: x[1],reverse=True)
    
    if len(counter) > 1:
        c1 = counter[0]
        c2 = counter[1]
    else:
        c1 = c2 = counter[0]
    
    return arr, c1, c2


prg_A, A1, A2 = prg_divide(0)
prg_B, B1, B2 = prg_divide(1)

if prg_A == prg_B:
    result = N // 2
elif A1[0] != B1[0]:
    result = ( len(prg_A) - A1[1] ) + ( len(prg_B) - B1[1] )
else:
    pattern = []
    pattern.append(( len(prg_A) - A2[1] ) + ( len(prg_B) - B1[1] ))
    pattern.append(( len(prg_A) - A1[1] ) + ( len(prg_B) - B2[1] ))
    pattern = sorted(pattern)
    result = pattern[0]
    
print(result)