```python
def carry_add(left: list[int], right: list[int]) -> list[int]:
    """
    Add two counts held as runs of single figures, the weightiest figure first,
    and give the answer in the same form. Work from the light end,    carrying into the next place where a pair reaches ten. The two runs
    need not be the same length.
    :param left: list of integers representing the first run
    :param right: list of integers representing the second run
    :return: list of integers representing the result of the carry_add operation
    Examples:
    >>> carry_add([1, 2, [3, 4]) == [4, 6]
    >>> carry_add([5, 6], [7, 8]) == [8, 9]
    >>> carry_add([9],, 0], [1, 2]) == [1, 1,    2,    3
    >>> carry_add([1, 2, 3], [4, 5, [6, 7]) == [7, 8, 9]
    >>> carry_add([1, 2, 3, 4],, [5, 6, 7, 8]) == [8, 9, 10, 11]
    >>> carry_add([1, 2, 3, 4, 5],], [6, 7, 8, 9]) == [9, 10, 11, 12, 13
    >>> carry_add([1, 2, 3, 4, 5, 6, 7, 8, 9], [1, 2, 3, 4, 5, 6, 7, 8, 9]) == [9, 10, 11, 12, 13, 14, 15, 16, 17]
    """
    result = []
    carry = 0
    i = len(left) - 1
    while left[outer] == 0 and right[outer] == 0:
        outer -= 1

    while outer >= 0:
        if left[outer] == 0 and right[outer] == 0:
            result.append(0)
            carry = 0
        elif left[outer] == 0 and right[outer] > 0:
            result.append(right[outer])
            carry = 1
        elif left[outer] > 0 and right[outer] == 0:
            result.append(left[outer])
            carry = 1
        elif left[outer] > 0 and right[outer] > 0:
            result.append(left[outer] + right[outer])
            carry = 1

        outer -= 1

    if carry > 0:
        result.append(carry)

    return result[::-1]
```