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())

v = [i for i in input().split()]

v1 = {}

v2 = {}

for i in range(n//2):
    if  v[2 *i +1] in v1.keys():
        v1[v[2 * i +1]] += 1
    else:
        v1[v[2 * i + 1]] = 1

    if v[2 * i] in v2.keys():
        v2[v[2 * i]] += 1
    else:
        v2[v[2 * i]] = 1


v1 = sorted(v1.items(),key=lambda x: - x[1])
v2 = sorted(v2.items(),key=lambda x: - x[1])
v1.reverse()
v2.reverse()
v1.append((None,0))
v2.append((None,0))
#print(v1)
if v1[0][0] == v2[0][0]:
    ans = max(v1[0][1]+v2[1][1] , v1[1][1] + v2[0][1])
else:
    ans = v1[0][1] + v2[0][1]

print(n - ans)