Box#697
A confectionery factory needs boxes for chocolates made from square cardboard sheets of size a \times a. The box should be open from the top and have a square base. The box is created in two steps. In the first step, square pieces of size b \times b are cut from each corner of the cardboard sheet. In the second step, the rectangular sides are folded up at a 90^\circ angle to form the box. Given the length of the cardboard sheet's side , find the height that maximizes the volume of the box.
The first line contains the number of tests (1 \leq n \leq 10). Each of the next lines contains a real number (1 \leq a \leq 10^{14}).
For each test, print the optimal height with decimal digits after the decimal point.
Example 1