When Leonardo da Vinci's famous painting "Mona Lisa's smile" was born, Leonardo da Vinci was ready to hang it on the wall. First, take a closer look. In order to hang the picture, you need to nail a nail in the wall. After the nail is nailed, the connecting line between the nail and the four corners of the wall divides the wall into several disjoint areas with an area greater than zero. Leonardo da Vinci is not only a master of art, but also a mathematical genius. He wanted to know: which of these disjoint areas has the smallest area? Can you help him figure it out? Suppose the wall is a square with side length A, and the distance between the nail and the upper and left margins of the wall are B and C respectively.
The input has multiple cases (no more than 100) of test data.
Each test case occupies one line, which are three integers A（1 ≤ A ≤ 100）、B（0 ≤ B ≤ A）and C（0 ≤ C ≤ A）, representing the side length of the square wall and the distance between the nail and the upper and left margins of the wall.
The end of input will be represented by a line of test case where A、B and C are equal to 0. This test case should not be processed.
Each test case outputs a line, which is a real number, that is, the area of the smallest area, which is rounded to one decimal place.
4 1 1
6 2 1
0 0 02.0
3.0