PROGRAMMING:Calculate the area of a circle
Enter the radius of the circle from the keyboard, calculate the area of the circle and output. Pi = 3.1415926.
###Input format:
Write the radius of the input circle here, for example:
three point six
###Output format:
Output the area of the circle here, for example:
forty point seven one five
###Input example:
```in
one point five
```
###Output example:
```out
seven point zero six eight five eight
```
answer：If there is no answer, please comment
###Input format:
Write the radius of the input circle here, for example:
three point six
###Output format:
Output the area of the circle here, for example:
forty point seven one five
###Input example:
```in
one point five
```
###Output example:
```out
seven point zero six eight five eight
```
answer：If there is no answer, please comment