import java.io.*;
import java.util.*;
class GCD
{
	public static void main(String args[])throws IOException
	{
		Scanner sc=new Scanner(System.in);
		System.out.println("Enter the numbers");
		int a=sc.nextInt();
		int b=sc.nextInt();
		System.out.println("GCD of a and b is "+gcd(a,b));
	}
	static int gcd(int a,int b)
	{
		if(a%b==0)
			return b;
		else
			return gcd(b,a%b);
	}
}