import sys


def read_n_integers(n: int) -> list[int]:
    """Reads stream inputs until exactly `n` integers are collected."""
    numbers = []
    # Reads tokens continuously from standard input
    for line in sys.stdin:
        numbers.extend(map(int, line.split()))
        if len(numbers) >= n:
            break
    return numbers[:n]


def match_pairs(wants_taller: list[int], wants_shorter: list[int]) -> int:
    """Greedily pairs individuals who want taller partners with those who want shorter partners.

    wants_taller: Heights of people needing a taller partner.
    wants_shorter: Heights of people needing a shorter partner.
    """
    wants_taller.sort()
    wants_shorter.sort()

    pairs_count = 0
    taller_idx = 0
    shorter_idx = 0

    while taller_idx < len(wants_taller) and shorter_idx < len(wants_shorter):
        # Check if the person expecting a shorter partner is taller than the required height
        if wants_shorter[shorter_idx] > wants_taller[taller_idx]:
            pairs_count += 1
            taller_idx += 1
            shorter_idx += 1
        else:
            # Person wanting a shorter partner is too short; test the next taller candidate
            shorter_idx += 1

    return pairs_count


def main():
    input_data = sys.stdin.read().split()
    if not input_data:
        return

    n = int(input_data[0])

    # Extract all elements for group 1 (men) and group 2 (women)
    arr1 = [int(x) for x in input_data[1 : n + 1]]
    arr2 = [int(x) for x in input_data[n + 1 : 2 * n + 1]]

    # Categorize Men
    men_want_taller = [x for x in arr1 if x > 0]
    men_want_shorter = [abs(x) for x in arr1 if x < 0]

    # Categorize Women
    women_want_taller = [x for x in arr2 if x > 0]
    women_want_shorter = [abs(x) for x in arr2 if x < 0]

    # Calculate valid pairs for both compatible configurations
    total_matches = match_pairs(
        women_want_taller, men_want_shorter
    ) + match_pairs(men_want_taller, women_want_shorter)

    print(total_matches)


if __name__ == "__main__":
    main()