from typing import Union
from typing import Any


def cast2lowercase(input: Union[list, tuple, str]) -> Any:
    """Cast input into lowercase.

    Example:
        >>> cast2lowercase('Hello World')
        'hello world'
        >>> cast2lowercase(['Hello', 'World'])
        ['hello', 'world']
    """
    inputs = []
    outputs = []
    if isinstance(input, str):
        inputs = [input]
    else:
        inputs = input  # type: ignore

    for _input in inputs:
        outputs.append(_input.lower())

    if isinstance(input, str):
        return outputs[0]
    elif isinstance(input, tuple):
        return tuple(outputs)
    else:
        return outputs