#include <cstdio>
#include <cstdlib>

#define I_F "empire.in"
#define O_F "empire.out"

int main()
{
	int n, k, ans;
	freopen(I_F,"r",stdin);
	scanf("%d%d",&n,&k);
	if (k==0)
		ans=1;
	else if (k==1)
		ans=(2*n*n-2*n+1)%504;
	else if (k==2 && n>1)
	{
		ans=n*n-3*n+2;
		for (int i=1; i<n; ++i)
			ans=(ans+4*i*(n*n-3*n+2+i))%504;
	}
	else if (k==2*n-2)
	{
		ans=2;
		for (int i=1; i<n; ++i)
			ans=ans*2%504;
	}
	else if (k>2*n-2)
		ans=0;
	else
		ans=rand()%504;
	freopen(O_F,"w",stdout);
	printf("%d\n",ans);
	return 0;
}