// Be sure that your data memory has at least 16 word locations
// since the stack pointer is initialized to location 15 (and stack
// grows downward.
//
// Also, the maximum value you can compute is sqr(6).  This is
// because each recursive call to sqr() needs to store two words
// on the stack.  To compute higher values, you will have to
// increase the size of your dmem *and* initialize $sp to a higher
// value.
00000000
00000003