PROGRAMMING:Finding the area of a circle
Write a program, according to the user input radius R (integer), calculate the semicircle arc length (hint: semicircle arc length should not add the length of diameter) and the semicircle area enclosed by the semicircle and the straight meridian. The value of PI is 3.14159.
###Input format:
Enter the integer radius R
###Output format:
Results two decimal places were reserved and output in the form of "len = semicircle arc length, area = semicircle area".
###Input example:
```in
ten
```
###Output example:
The corresponding output is given here. For example:
```out
len=31.42,area=157.08
```
answer：If there is no answer, please comment
###Input format:
Enter the integer radius R
###Output format:
Results two decimal places were reserved and output in the form of "len = semicircle arc length, area = semicircle area".
###Input example:
```in
ten
```
###Output example:
The corresponding output is given here. For example:
```out
len=31.42,area=157.08
```
answer：If there is no answer, please comment