/* A program to perform Euclid's 
   Algorithm to compute gcd. */

int gcd( int u, int v )
{
	if( v == 0 )
		return u;
	else
		return gcd( v, u-u/v*v);
	/* u-u/v*v == u mod v */
}

void main( void )
{
	int x, y;
	read(x);
	read(y);
	write( gcd(x,y) );
}