allocate mem(2^30)

tr(v)=if (v>=0, 1+2*v, -2*v)
big = 100000
s = []
S = []
seen(z)=my (x=tr(real(z)),y=tr(imag(z)));if (max(x,y)>big, setsearch(S,z), x>#s, 0, bittest(s[x],y))
see(z)=my (x=tr(real(z)),y=tr(imag(z)));if (max(x,y)>big, S=setunion(S,Set(z)); return, x>#s, s=concat(s,vector(x-#s))); s[x]=bitor(s[x],2^y)

neighbours(z) = {
	[ z + (-1)^imag(z),
	  z + (1+I)*(-1)^(imag(z)+real(z)),
	  z + I*(-1)^real(z) ]
}

{
	gen = [1+I];

	for (n=0, M=2^13,
		print (n " " #gen);

		if (n<M,
			apply (see, gen);
			gen = select(z -> !seen(z), Set(concat(apply (neighbours, gen))));
		);
	);
}

quit