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()))

v_e_cnt = [0 for i in range(10**6)]
v_o_cnt = [0 for i in range(10**6)]
for x in range(n):
	if x % 2 == 0:
		v_e_cnt[v[x]] += 1
	else:
		v_o_cnt[v[x]] += 1

max_e = [(0,0),(0,0)]
max_o = [(0,0),(0,0)]
for i in range(10**5+1):
	if max_e[1][0] < v_e_cnt[i]:
		if max_e[0][0] < v_e_cnt[i]:
			max_e[1] = max_e[0]
			max_e[0] = (v_e_cnt[i], i)
		else:
			max_e[1] = (v_e_cnt[i], i)
	if max_o[1][0] < v_o_cnt[i]:
		if max_o[0][0] > v_o_cnt[i]:
			max_o[1] = max_o[0]
			max_o[0] = (v_o_cnt[i], i)
		else:
			max_o[0] = (v_o_cnt[i], i)

ans = n - e[0][0] - o[0][0]
if e[0][1] == o[0][1]:
	ans = n - max(e[0][0] + o[1][0], e[1][0] + o[0][0])

print(ans)