{ vv = 0; dd = 0; unseen = 1; v = 1; for (n=0, 25 000, print (n " " unseen); vv += 2^v; while (bittest(vv, unseen), unseen++; ); for (w=unseen, oo, if (!bittest(vv,w) && !bittest(dd, d=abs(v-w)), v = w; dd += 2^d; break; ); ); ); } quit