PROGRAMMING:Calculate the area according to the radius.
Write the code to calculate the circle area, the radius is input by the user, and the PI is defined as 3.14159.
###Input format:
Enter integer radius
###Output format:
The area is calculated and output according to the radius. The result retains 2 decimal places and is output in the form of "area = area".
###Input example:
```in
one
```
###Output example:
```out
area = 3.14
```
answer：If there is no answer, please comment
###Input format:
Enter integer radius
###Output format:
The area is calculated and output according to the radius. The result retains 2 decimal places and is output in the form of "area = area".
###Input example:
```in
one
```
###Output example:
```out
area = 3.14
```
answer：If there is no answer, please comment