#include <stdio.h>  
#include <math.h> 
FILE *f;   
long a,b;   
int main(void){   
    f=fopen("cmmdc.in","r");   
    fscanf(f,"%ld %ld",&a,&b);   
    fclose(f);   
    f=fopen("cmmdc.out","w");   
    long int r,aux;   
    if (a<b){   
        aux=a;   
        a=b;   
        b=aux;   
    }   
    else {}   
       
    while (b != 0){   
        r=a%b;   
        a=b;   
        b=r;   
    }   
       
    fprintf(f,"%ld",a);   
       
    fclose(f);   
}