window_sliding_technique.py

large_number = '6717483933'
large_number_array = list(map(int, large_number))


def count_max_sum(window_size):
    if len(large_number) < window_size:
        return -1

    max_sum = 0
    for i in range(0, window_size):
        max_sum += large_number_array[i]

    window_sum = max_sum
    for i in range(window_size, len(large_number_array)):
        window_sum += large_number_array[i] - large_number_array[i - window_size]
        max_sum = max(max_sum, window_sum)
    return max_sum


print(count_max_sum(4))