PROGRAMMING:Judging the shape of a triangle

Input three positive integers, first judge whether the three data can form a triangle (the sum of any two sides is greater than the third side), if it can form a triangle, continue to judge whether it is an equilateral triangle or an isosceles triangle or a right triangle.
###Input format:
Enter 3 positive integers.
###Output format:
It can not form triangle output "no", it can form triangle output "equilateral" or "isosceles" or "right angle" or "ordinary triangle".
###Input sample 1:
```in
3 4 5
```
###Output sample 1:
```out
right angle
```
###Input sample 2:
```in
3 4 1
```
###Output sample 2:
```out
NO
```







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