#include <fstream>
using namespace std;

int main()
{
	ifstream input("cmmdc.in");
	
	unsigned int nA, nB;
	input >> nA >> nB;
	input.close();
	
	unsigned int nCMMDC = 0;
	for (unsigned int iii = 2; 	iii <= ( (nA+nB > 30000) ?30000 :(nA+nB) );	iii++)
		if ( (!(nA%iii)) && (!(nB%iii)) ) nCMMDC = iii;
	
	ofstream output("cmmdc.out");

	output << nCMMDC;
	output.close();
	
	return 0;
}