#include<stdio.h>  
      
    int cmmdc(int a,int b){  
        if(a==0) return b;  
        else if(b==0) return a;  
            else return cmmdc(b, a%b);  
     }  
  
   
   int main(){  
       int a,b;
	freopen("euclid2.in", "r" ,stdin);
	freopen("euclid2.out", "w" ,stdout);  
       scanf("%d %d",&a,&b);  
       printf("%d",cmmdc(a,b));  
       return 0;  
       }