```java
public static int gcd(int m,int n){
if (m%n==0){
return n;
}
return gcd(n,m%n);
}
```
```java
public static int GCD(int m,int n){
if (m==n){
return m;
}
if (m>n){
return GCD(m-n,n);
}
else{
return GCD(m,n-m);
}
}
```