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 = list(map(int, input().split()))
v1 = []
v2 = []
for i in range(n):
	if i%2 == 0:
		v1.append(v[i])
	else:
		v2.append(v[i])
v1.sort()
v2.sort()

cnt1 = []
cnt2 = []
now = v1[0]
con = 1
for i in range(1, len(v1)):
	if now == v1[i]:
		con += 1
	else:
		now = v1[i]
		cnt1.append(con)
		con = 1
cnt1.append(con)
now = v2[0]
con = 1
for i in range(1, len(v2)):
	if now == v2[i]:
		con += 1
	else:
		now = v2[i]
		cnt2.append(con)
		con = 1
cnt2.append(con)
cnt1.sort()
cnt2.sort()
print(sum(cnt1[:len(cnt1)-1])+sum(cnt2[:len(cnt2)-1]))