NPY and shot

NPY is going to have a PE test.One of the test subjects is throwing the shot.The height of NPY is H meters.He can throw the shot at the speed of v0 m/s and at the height of exactly H meters.He wonders if he throws the shot at the best angle,how far can he throw ?(The acceleration of gravity, g, is $9.8m/s^2$)

The first line contains a integer $T(T \leq 10000)$,which indicates the number of test cases.
The next T lines,each contains 2 integers $H(0 \leq h \leq 10000m)$,which means the height of NPY,and $v_0(0 \leq v_0 \leq 10000m/s)$, which means the initial velocity.

For each query,print a real number X that was rounded to 2 digits after decimal point in a separate line.X indicates the farthest distance he can throw.

2
0 1
1 2

0.10
0.99

If the height of NPY is 0,and he throws the shot at the 45° angle, he can throw farthest.

BestCoder Round #22