readsb
if (readsb(1) == 0) {
if (readsb(0) != 0)
static int readsb(int);
if (readsb(1) == 0) {
if (readsb(0) != 0 &&
if (readsb(0) != 0 &&
if (readsb(0) != 0 &&
static int readsb(int);