PROGRAMMING:Enter the radius (greater than 0) to calculate the circle area
This topic requires input radius (greater than 0), and calculate the circle area.
Note: if the radius entered is not greater than 0, you will be prompted to continue to enter until you enter a qualified radius.
###Input format:
Enter a number on a line
###Output format:
The area of a circle with radius result1 is result2
Where result1 is the radius and result2 is the area of the circle
###Input example:
Here is a set of inputs. For example:
```in
five
```
###Output example:
The corresponding output is given here. For example:
```out
The area of a circle with radius 5 is 78.5
```
answer：If there is no answer, please comment
Note: if the radius entered is not greater than 0, you will be prompted to continue to enter until you enter a qualified radius.
###Input format:
Enter a number on a line
###Output format:
The area of a circle with radius result1 is result2
Where result1 is the radius and result2 is the area of the circle
###Input example:
Here is a set of inputs. For example:
```in
five
```
###Output example:
The corresponding output is given here. For example:
```out
The area of a circle with radius 5 is 78.5
```
answer：If there is no answer, please comment