Should the answer for this be $-16$ or $16?$ The following instructions are used to save registers into the stack:

sw$$ra$,12($sp$)$ # save ra on the stack

sw s$2,8($sp$)$ # save s$2$ on the stack

sw$$s$1,4($sp$)$# save s$1$ on the stack

sw$$s$0,0($sp$)$# save s$0$ on the stack

Before the first of these$$sw$$instructions is executed a value has to be added to the$$sp$$register$.$

What is the value that should be added to$$sp$?$

For automated grading, do not use spaces in your answer