"Now,
mark ye,
fine fellows," said Sir Hugh to some who had
besought him
to explain, "that at the very first start there be two ways open:
whichever B ye select, there will be two several ways of proceeding
(twice times two are four); whichever R ye select, there be two ways of
going on (twice times four are eight); and so on until the
end.

Each
letter in order from A downwards may so be reached in 2, 4, 8, 16, 32,
etc., ways.

Therefore,
as there be ten lines or steps in all from A to
the bottom, all ye need do is to multiply ten 2's together, and truly
the
result, 1024,
is the answer thou dost seek."