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 OCaml (4.02.3) (judge verdict: Wrong Answer)

Scanf.(Array.(let s,q,a,c,f,d=(fun f->Scanf.scanf" %d"f),make 100005(0,0),(fun a i->a.(i)<-fst a.(i)+1,i),(fun u v->compare v u),fst,snd in s@@fun n->let e,o=init n(fun i->s@@fun v->i,v)|>fold_left(fun(e,o)(i,v)->(if i mod 2=0 then a e v else a o v);e,o)(q,q)in sort c e;sort c o;print_int@@n-(if d e.(0)=d o.(0)then max(f e.(0)+f o.(1))(f e.(1)+f o.(0))else(f e.(0)+f o.(0)));0,0))