Largest inscribed rectangle

Input

First line contains the number of test cases $t$ (1 \le t \le 1000). Next $t$ lines each contain two integers $r$ and $b$ (1 \le r, b \le 10000).

Output

For each test case print on a separate line the maximum area of a rectangle whose shorter side does not exceed $b$ that can be inscribed into a circle of radius $r$. Your answer should be rounded to three digits after the decimal point (see sample output).

Examples