PROGRAMMING:Calculate the area of a circle
This topic requires reading in the radius of a circle, an integer R, calculating and outputting the area of the circle. The value of PI is 3.14.
###Input format:
Enter the integer value r that gives the radius of a circle in a row.
###Output format:
Area = area of the circle with 2 decimal places.
###Input example:
Here is a set of inputs. For example:
```in
two
```
###Output example:
The corresponding output is given here. For example:
```out
area=12.56
```
answer：If there is no answer, please comment
###Input format:
Enter the integer value r that gives the radius of a circle in a row.
###Output format:
Area = area of the circle with 2 decimal places.
###Input example:
Here is a set of inputs. For example:
```in
two
```
###Output example:
The corresponding output is given here. For example:
```out
area=12.56
```
answer：If there is no answer, please comment