Problems
Throwing dice
Throwing dice
A dice with faces numbered from $1$ to $6$ is rolled $n$ times. Find the probability that the sum of all the rolled numbers will be exactly $q$.
\InputFile
Two integers $n$ and $q~(1 \le n \le 500, 1 \le q \le 3000)$.
\OutputFile
Print the required probability with at least two decimal places.
Input example #1
1 6
Output example #1
0.16666