e793-2

/* e793 - 2 */
#include <cstdio>

using namespace std;

using int64 = long long;

typedef int64(*Fun)(int64 a, int64 b);
struct gcd_solver
{
    Fun gcd;
};

gcd_solver arr[2] = { [](int64 a, int64 b) { return a; }, [](int64 a, int64 b) { return arr[!!(a % b)].gcd(b, a % b); } };

int main()
{
    int64 X, Y;

    while (scanf("%lld %lld", &X, &Y), X || Y)
    {
        printf("%lld\n", arr[!!Y].gcd(X, Y));
    }

    return 0;
}