Problem C - Puzzled sheep

There is a circle of grass with the radius R. We want to let a sheep eat the grass from that circle by attaching the sheep's leash on the edge of the circle. What must be the length L of the leash for the sheep to eat exactly X% of the grass?

Input consists of a sequence of lines each containg two non-negative integers separated by whitespace. The first integer is the value of R and the second is the value of X, 0 <= X <= 100.

For each input line, output a single real number with 5 digits of the fraction, giving the required length of the leash.

Sample input

10 50
50 10
10 0
20 100
37 37
1000 50

Output for sample input

11.58728
23.57857
0.00000
40.00000
35.82576
1158.72847