Dance Party

N men and N women came to a dance party. The host knows every person's height and what kind of height that person prefers in a dance partner. Each person can dance with at most one other person, and each pair consists of one man and one woman.

Each man prefers exactly one of two types of women: women taller than him or women shorter than him. Each woman likewise prefers exactly one of two types of men: men taller than her or men shorter than her. Two people of the same height never form a dance pair.

Given every person's height and preference type, find the maximum number of dance pairs that can be made while satisfying both people in every pair.

The first line contains N. (1 <= N <= 100,000)

The second line contains the height information of the N men in millimeters. The absolute value of each integer is the person's actual height and is between 1500 and 2500, inclusive. A positive value means the man wants to dance with a taller woman, and a negative value means he wants to dance with a shorter woman.

The third line contains the height information of the N women in the same format. A positive value means the woman wants to dance with a taller man, and a negative value means she wants to dance with a shorter man.

Print the maximum number of dance pairs that can be made.