import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int b = scan.nextInt();
//将两数之差赋给较大者,直到两数相等
        while(a!=b){
            a = a>b?a-b:a;
            b = a<b?b-a:b;
        }
         System.out.println(a);

    }
}