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)

import numpy as np,math,itertools


n=int(input())
v=list(map(int,input().split()))
va,vb=[],[]
v2=[]

for i in range(n):
   if i%2==0:va+=[v[i]]
   else:vb+=[v[i]]

def hkk(a,b):
   s=0
   for i in range(min(len(a),len(b))):
      if a[i]!=b[i]:s+=1
   return s

def hsm(a):
   q=[0 for i in range(10001)]
   for i in a:
      q[i]+=1
   c=max(q)
   z=0
   while q[z]!=c:z+=1
   return z


ha=hsm(va)
hb=hsm([i for i in vb if i!=ha])

for i in range(n):
   v2+=[ha]
   v2+=[hb]

print(hkk(v,v2))