1 start := 1000;

     2 x := start;

     3 y := start;

     4 z := start;

     5 while 0 < x do {

     6  while 0 < y do {

     7   while 0 < z do {

     8     z := z - 1

     9   };

    10   z := start;

    11   y := y - 1

    12  };     

    13  y := start;

    14  x := x - 1

    15 };

    16 write x;

    17 write y;

    18 write z