def total_coffee(num_cups: int, amount_per_cup: int) -> int:
    """Return the total possible amount in millilitres 
     of coffee for num_cupsbcups where each 
    cup can hold amount_per_cup.
    
    >>> total_coffee(10, 100)
    1000
    >>> total_coffee(0, 600)
    0
    >>> total_coffee(600, 0)
    0
    """
    
    return num_cups * amount_per_cup