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())

l=list(map(int,input().split()))
l1=[]
l2=[]

for i in range(n):
	if i%2==0:
		l1.append(l[i])
	else:
		l2.append(l[i])

count1=[]
count2=[]

for i in range(100000):
	count1.append(0)
	count2.append(0)

for i in range(n//2):
	count1[l1[i]-1]+=1
	count2[l2[i]-1]+=1

max1=0
max2=0

maxc1=[]
maxc2=[]

for i in range(100000):
	if count1[i]>=max1:
		max1=count1[i]
		maxc1.append(i)

	if count2[i]>=max2:
		max2=count2[i]
		maxc2.append(i)

# print('maxc1',maxc1)
# print('maxc2',maxc2)
# print('max1',max1)
# print('max2',max2)

# if len(maxc2)+len(maxc1)>2 or (len(maxc2)+len(maxc1)==2 and maxc1[0]!=maxc2[0]):
# 	final=max1+max2

# else :
max3=0
max4=0
for i in range(100000):
	if i!=maxc1[0]:
		if count1[i]>=max3:
			max3=count1[i]
			maxc1.append(i)

	if i!=maxc2[0]:
		if count2[i]>=max4:
			max4=count2[i]
			maxc2.append(i)

final=max(max1+max4,max2+max3)

print(n-final)