def largest_sum(int_list):
    """Return the maximum sum of of all the possible contiguous subarrays.

    Input is an array of integers. All possible summations of contiguous
    subarrays are calulated and the maximum is updated whenever a sum is
    greater than the current maximum.

    Args:
        int_list: A list of integers

    Returns:
        max_sum: An integer that is the maximum sum found.
    """
    max_sum = float("-inf")
    for i in range(len(int_list)):
        for j in range(i + 1, len(int_list) + 1):
            current_sum = sum(int_list[i:j])
            # print(int_list[i:j])
            if current_sum > max_sum:
                max_sum = current_sum
    return max_sum