#include<stdio.h>
int gcd;
void GCD(int,int);
int main()
{
    int n1,n2,gcd;
    printf("Enter the two numbers  :\n");
    scanf("%d%d",&n1,&n2);
    GCD(n1,n2);
}
void GCD(int x,int y)
{
    int c;
    if(x==0 )
    {
        gcd=y;
        printf("GCD=%d\n",gcd);
    }
    else if(y==0)
    {
        gcd=x;
        printf("GCD=%d\n",gcd);
    }
    else if(x>y)
    {
        x=x-y;
        GCD(x,y);
    }
    else
    {
        y=y-x;
        GCD(x,y);
    }

}