PROGRAMMING:Finding the greatest common divisor by Division
To find the greatest common divisor of two positive integers by division.
###Input format:
Input gives 2 positive integers on a line, separated by commas.
###Output format:
Output the greatest common divisor of two integers in the order of "GCD = greatest common divisor" in one line.
###Input example:
```in
15,20
```
###Output example:
```out
gcd=5
```
answer：If there is no answer, please comment
###Input format:
Input gives 2 positive integers on a line, separated by commas.
###Output format:
Output the greatest common divisor of two integers in the order of "GCD = greatest common divisor" in one line.
###Input example:
```in
15,20
```
###Output example:
```out
gcd=5
```
answer：If there is no answer, please comment