Anka was awarded a medal and given a buttered toast for displaying heroism
in a combat. The toast was so narrow, flat, and thin that it could be
regarded as a straight-line segment of length l. On Commissar Matroskin's
advice, Anka turned the toast the buttered side down and, holding it parallel
to the ground, brought it to her mouth and was ready to bite,
when suddenly…
The toast slipped out of her hands and started falling under gravity. It was
rotating at a constant angular velocity about its center of mass in the
plane perpendicular to the ground, as shown in the picture.
Your task is to determine which side of the toast touched the ground first.
Input
The first line contains the length l of the toast in centimeters,
the distance h from Anka's mouth to the ground in centimeters,
and the angular velocity ω of the toast's rotation in revolutions
per minute (the toast makes one revolution when it turns 360 degrees).
1 ≤ l, h, ω ≤ 1000. These numbers are integers
separated with a space. The acceleration of gravity should be taken equal to
9.81 m/s2.
Output
Output “butter” if the toast first touched the ground the buttered side
down and “bread” otherwise. It is guaranteed that at the moment the toast
touched the ground for the first time it wasn't orthogonal to it.
Samples
input | output |
---|
10 400 15
| butter
|
10 500 15
| bread
|
Problem Author: Alex Samsonov
Problem Source: NEERC 2010, Eastern subregional contest