a = 0; b = 0; c = 0;
   a(60) = 1;
   do i = 1 to 64; /* Generate 2**64 */
      call add (a, a, b);
      put skip;
      call output (b);
      a = b;
   end;
   call multiply (a, b, c);
   put skip;
   call output (c);