Three sides of a triangle a, b, c are given. Determine the type of triangle with given sides. Print one of four words: rectangular for a right triangle, acute for an acute triangle, obtuse for an obtuse triangle, or impossible if no triangle with such sides exists.
Input data: Three natural numbers are entered.
Output: Print the answer to the problem.
Examples
| # |
Input |
Output |
| 1 |
3
4
5 |
rectangular |
| 2 |
1
2
3 |
impossible |