#include <iostream>
using namespace std;
int main() {
int a, b;
cin >> a >> b;
int scifa = 0, scifb = 0;
while(a > 0) {
scifa = scifa + a % 10;
a = a / 10;
}
while(b > 0) {
scifb = scifb + b % 10;
b = b / 10;
}
int rest;
while(scifb > 0) {
rest = scifa % scifb;
scifa = scifb;
scifb = rest;
}
cout << scifa;
return 0;
}