x := y := z := 105;

n := read ();

write (x);
write (y);
write (z);

if z then x else y fi := 230;

write (x);
write (y);
write (z);

(write (z); z) := 250;

write (x);
write (y);
write (z);

s := [1, 2, 3, 4];
i := -1;

while n := s[i := i + 1]; n == 1 !! n == 2 !! n == 3 do
  write (n)
od