def decode_seat_string(seat):
    """
    Test data

    BFFFBBFRRR: row 70, column 7, seat ID 567.
    FFFBBBFRRR: row 14, column 7, seat ID 119.
    BBFFBBFRLL: row 102, column 4, seat ID 820.

    Seat string is 10 bits binary

    B = 1
    F = 0
    R = 1
    L = 0
    """
    bin_seat_number = seat.replace('B', '1').replace('F', '0').replace('L', '0').replace('R', '1')
    return int(bin_seat_number, 2)