lines = open("input.txt", "r").read().splitlines()

sand_source = (500, 0)


def parse_rocks(lines: list) -> list:
    paths = []
    for line in lines:
        path = [int(c) for coord in line.split(" -> ") for c in coord.split(",")]
        paths.append(path)
    rocks = set()
    for path in paths:
        for i in range(0, len(path) - 2, 2):
            x1, y1 = path[i], path[i + 1]
            x2, y2 = path[i + 2], path[i + 3]
            xrange = range(min(x1, x2), max(x1, x2) + 1)
            yrange = range(min(y1, y2), max(y1, y2) + 1)
            coords = [(x, y) for x in xrange for y in yrange]
            rocks.update(coords)
    return rocks


def drop_sand(rocks, max_y):
    x, y = sand_source
    while True:
        if (x, y) in rocks:
            x, y = sand_source
        if (x, y + 1) not in rocks and y < max_y + 1:
            y += 1
        elif (x - 1, y + 1) not in rocks and y < max_y + 1:
            x -= 1
            y += 1
        elif (x + 1, y + 1) not in rocks and y < max_y + 1:
            x += 1
            y += 1
        else:
            rocks.add((x, y))
            print(len(rocks) - onlyrocks)
        if (x, y) == sand_source:
            break
    return rocks


def get_max_y(rocks):
    max_y = sorted(rocks, key=lambda x: x[1])[-1][1]
    return max_y


rocks = parse_rocks(lines)
onlyrocks = len(rocks)
max_y = get_max_y(rocks)
rocksandsand = drop_sand(rocks, max_y)
print(len(rocksandsand) - onlyrocks)