#include <bits/stdc++.h>
//#define endl '\n'
//#define ll long long
using namespace std;
string sa, sb;
vector <short> jian(vector <short> x, vector <short> y)
{
	vector <short> ret(x.size() + 1, 0);
	for (int i = 1; i < min(x.size(), y.size()); i++)
	{
		if (x[i] - y[i] < 0)
		{
			x[i + 1] --;
			ret[i] = x[i] + 10 - y[i];
		}
		else
		{
			ret[i] = x[i] - y[i];
		}
	}
	return ret;
}
vector <short> cheng(vector <short> y)
{
	for (short &v : y)
	{
		v *= 2;
	}
	for (int i = 0; i < y.size(); i ++)
	{
		if (i == y.size() - 1 && y[i] >= 10)y.push_back(0);
		y[i + 1] += y[i] / 10;
		y[i] %= 10;
	}
	return y;
}
vector <short> chu(vector <short> x, short y)
{
	vector <short> ret;
	reverse(x.begin(), x.end());
	short v = 0;
	for (int i = 0; i < x.size(); i++)
	{
		if (!x[i] && !v && ret.size())
		{
			ret.push_back(0);
			continue;
		}
		v = v * 10 + x[i];
		if (v < y)ret.push_back(0);
		else
		{
			ret.push_back(v / y);
			v %= y;
		}
	}
	reverse(ret.begin(), ret.end());
	return ret;
}
bool small(vector <short> x, vector <short> y)
{
	reverse(x.begin(), x.end());
	reverse(y.begin(), y.end());
	string a, b;
	bool flag = false;
	for (int v : x)
	{
		if (flag || v)
		{
			flag = true;
			a.push_back(v + '0');
		}
	}
	flag = false;
	for (int v : y)
	{
		if (flag || v)
		{
			flag = true;
			b.push_back(v + '0');
		}
	}
	if (a.size() != b.size())return a.size() < b.size();
	else return a < b;
}
bool same(vector <short> x, vector <short> y)
{
	reverse(x.begin(), x.end());
	reverse(y.begin(), y.end());
	string a, b;
	bool flag = false;
	for (int v : x)
	{
		if (flag || v)
		{
			flag = true;
			a.push_back(v + '0');
		}
	}
	flag = false;
	for (int v : y)
	{
		if (flag || v)
		{
			flag = true;
			b.push_back(v + '0');
		}
	}
	return a == b;
}
vector <short> gcd(vector <short> a, vector <short> b)
{
	/*for (int i = 0; i < a.size(); i++)
		cout << a[i];
	cout << '\n';
	for (int i = 0; i < b.size(); i++)
		cout << b[i];
	cout << '\n';*/
	
	if (same(a, b))return a;
	else if (small(a, b)) return gcd(b, a);
	else if (a[1] % 2 == 0)
	{
		if (b[1] % 2 == 0)return cheng(gcd(chu(a, 2), chu(b, 2)));
		else return gcd(chu(a, 2), b);
	}
	else
	{
		if (b[1] % 2 == 0)return gcd(a, chu(b, 2));
		else return gcd(b, jian(a, b));
	}
}
int main()
{
	cin >> sa >> sb;
	vector <short> a(sa.size() + 1, 0);
	vector <short> b(sb.size() + 1, 0);
	for (int i = 0; i < sa.size(); i++)
	{
		a[sa.size() - i] = sa[i] - '0';
	}
	for (int i = 0; i < sb.size(); i++)
	{
		b[sb.size() - i] = sb[i] - '0';
	}
	vector <short> ans = gcd(a, b);
	reverse(ans.begin(), ans.end());
	ans.pop_back();
	bool flag = false;
	for (short x : ans)
	{
		if (x)flag = true;
		if (flag)cout << x;
	}
	return 0;
}