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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def remove_leading_zeros(num: str) -> str: """ Strips zeros while handling -, M, and empty strings """

    if not num:
        return num
    if num.startswith('M'):
        ret = 'M' + num[1:].lstrip('0')
    elif num.startswith('-'):
        ret = '-' + num[1:].lstrip('0')
    else:
        ret = num.lstrip('0')
    return '0' if ret in ('', 'M', '-') else ret