#30147: ___c
#include<stdio.h>
//求最大公因數
int gcd(int a, int b);
int main(){
int a = 0, b = 0;
scanf("%d %d", &a, &b);
printf("%d",gcd(a, b));
return 0;
}
int gcd(int a, int b){
if(a < b){
gcd(b,a);
}
if(a % b == 0){
return b;
}
else return gcd(b, a % b);
}