def clear_bit(S, j):
    """
    Returns a new set from set `S` with the `j`-th item turned off.

    Examples
    ========

    Clear/turn off item in position 1 of the set:
    >>> S = 0b101010
    >>> bin(clear_bit(S, 1))
    '0b101000'

    """
    return S & ~(1 << j)