Problem A
Pizza Crust
George has bought a pizza. George loves cheese. George thinks the pizza does not have enough cheese. George gets angry.
George’s pizza is round, and has a radius of $R$ cm. The outermost $C$ cm is crust, and does not have cheese. What percent of George’s pizza has cheese?
Input
The input consists of a single line with two space separated integers, $R$ and $C$.
Output
Output the percentage of the pizza that has cheese. Your answer must have an absolute or relative error of at most $10^{6}$.
Limits

$1 \leq C \leq R \leq 100$
Sample Input 1  Sample Output 1 

1 1 
0.000000000 
Sample Input 2  Sample Output 2 

2 1 
25.000000 