import numpy as np

file = "inputs/day9.input"
numbers = [x.decode().replace("\n", "") for x in open(file, "rb").readlines()]
numbers = [[int(x) for x in number] for number in numbers]
numbers = np.array(numbers)

coords = []

for x in range(numbers.shape[0]):
    for y in range(numbers.shape[1]):
        if x == 0 and y == 0:
            if numbers[x + 1, y] > numbers[x, y] and numbers[x, y + 1] > numbers[x, y]:
                coords.append((x, y))
        elif x == 0 and y == numbers.shape[1] - 1:
            if numbers[x + 1, y] > numbers[x, y] and numbers[x, y - 1] > numbers[x, y]:
                coords.append((x, y))
        elif x == numbers.shape[0] - 1 and y == 0:
            if numbers[x - 1, y] > numbers[x, y] and numbers[x, y + 1] > numbers[x, y]:
                coords.append((x, y))
        elif x == numbers.shape[0] - 1 and y == numbers.shape[1] - 1:
            if numbers[x - 1, y] > numbers[x, y] and numbers[x, y - 1] > numbers[x, y]:
                coords.append((x, y))
        elif x == 0 and y > 0 and y < numbers.shape[1] - 1:
            if (
                numbers[x, y + 1] > numbers[x, y]
                and numbers[x, y - 1] > numbers[x, y]
                and numbers[x + 1, y] > numbers[x, y]
            ):
                coords.append((x, y))
        elif x == numbers.shape[0] - 1 and y > 0 and y < numbers.shape[1] - 1:
            if (
                numbers[x, y + 1] > numbers[x, y]
                and numbers[x, y - 1] > numbers[x, y]
                and numbers[x - 1, y] > numbers[x, y]
            ):
                coords.append((x, y))
        elif y == 0 and x > 0 and x < numbers.shape[0] - 1:
            if (
                numbers[x, y + 1] > numbers[x, y]
                and numbers[x - 1, y] > numbers[x, y]
                and numbers[x + 1, y] > numbers[x, y]
            ):
                coords.append((x, y))
        elif y == numbers.shape[1] - 1 and x > 0 and x < numbers.shape[0] - 1:
            if (
                numbers[x, y - 1] > numbers[x, y]
                and numbers[x - 1, y] > numbers[x, y]
                and numbers[x + 1, y] > numbers[x, y]
            ):
                coords.append((x, y))
        else:
            if (
                numbers[x, y - 1] > numbers[x, y]
                and numbers[x, y + 1] > numbers[x, y]
                and numbers[x - 1, y] > numbers[x, y]
                and numbers[x + 1, y] > numbers[x, y]
            ):
                coords.append((x, y))


def get_candidates(tup):
    candidates = []
    x, y = tup
    if x != 0 and numbers[x - 1, y] != 9 and numbers[x - 1, y] > numbers[x, y]:
        candidates.append((x - 1, y))
    if (
        x != numbers.shape[0] - 1
        and numbers[x + 1, y] != 9
        and numbers[x + 1, y] > numbers[x, y]
    ):
        candidates.append((x + 1, y))
    if y != 0 and numbers[x, y - 1] != 9 and numbers[x, y - 1] > numbers[x, y]:
        candidates.append((x, y - 1))
    if (
        y != numbers.shape[1] - 1
        and numbers[x, y + 1] != 9
        and numbers[x, y + 1] > numbers[x, y]
    ):
        candidates.append((x, y + 1))

    return candidates


def get_basin(tup):
    basin = []
    starts = [tup]
    while len(starts) > 0:
        for start in starts:
            candidates = get_candidates(start)
            for candidate in candidates:
                if candidate not in basin and candidate not in starts:
                    starts.append(candidate)
            basin.append(start)
            starts.remove(start)
    return basin


basin_lengths = []
for coord in coords:
    basin_lengths.append(len(get_basin(coord)))

lengths = sorted(basin_lengths)
print(lengths[-3] * lengths[-2] * lengths[-1])