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)

a = int(input())

b = list(map(int,input().split()))
d = max(b)
c = [0 for i in range(pow(10,5))]
cc = [0 for i in range(pow(10,5))]
for i in range(a):
    if i % 2 == 0:
        c[b[i]-1] += 1
    else:
        cc[b[i]-1] += 1

one = 0
onee = 0
two = 0
twoo = 0
p = 0
pp = 0
for i in range(d):
    if one < c[i]:
        onee = one
        one = c[i]
        p += 1
    if two < cc[i]:
        twoo = two
        two = cc[i]
        p += 1
    if p == 2:
        pp = 1
    else:
        pp = 0
    p = 0

t = max(one+twoo,onee+two)

if pp == 0:
    print(a-one-two)
else:
    print(a-t)