brute_force.py

def ex8(window_size):
    large_number = open("source.txt", 'r').read()

    max_product = 1
    for i in range(0, len(large_number)):
        product = 1
        if i + window_size <= len(large_number):
            for j in range(i, i + window_size):
                product *= int(large_number[j])
        max_product = max(max_product, product)

    return max_product


assert ex8(4) == 5832
print(ex8(13))