Problem Statement

A prime die is a die whose faces have the integers \(2,3,5,7,11,13\) written on them.
A composite die is a die whose faces have the integers \(4,6,8,9,10,12\) written on them.
Write a program that finds the expected value of the product of the numbers rolled when $P$ prime dice and $C$ composite dice, for a total of $P+C$ dice, are rolled at the same time.
Each face comes up with probability $1/6$, and the faces rolled on the dice are independent of each other.

Input

$P$ $C$

$0 \leq P \leq 5$
$0 \leq C \leq 5$
$P+C \geq 1$

Output

Output the answer. A relative error of up to $10^{-9}$ is allowed.

Sample

1 0

6.83333333333333333

3 4

1419309.59119584458