PROGRAMMING:C programming experiment 4-7 prime search task 4

Input an integer m arbitrarily from the keyboard, if M is not a prime, then calculate and output all its factors (excluding 1);
If M is a prime number, output "it is a prime number"
###Input format:
Any integer
###Output format:
If M is not a prime number, calculate and output all its factors (excluding 1), separated by English commas. Note that there is no comma after the last number (no comma before the first number);
Note: if you enter a negative number, you should also output all its factors.
If M is a prime number, output "it is a prime number"
###Input example:
Here is a set of inputs. For example:
```in
sixteen
```
###Output example:
The corresponding output is given here. For example:
```out
2,4,8
```







answer：If there is no answer, please comment