import java.util.*;
public class main{
    public static void main(String[] args) {
        try{
            int x,y;
            Scanner in=new Scanner(System.in);
            x=in.nextInt();
            y=in.nextInt();
            in.close();
            
            System.out.print(gcd(x,y));
        }catch(Exception e){
            System.out.println("Input error!");
        }
    }
    public static int gcd(int a,int b)
    {
    	if(a<b)
    	{
    		int tmp=b;
    		b=a;
    		a=tmp;
    	}
    	if(a%b!=0)
    		return gcd(b,a%b);
    	else
    		return b;
    }
};