Consider the following instruction: Add offset$($rd$),$rs$,$rt

Interpretation: MEMR$|[$rd$]+$ sign$\_$extend$($offset$)]<-$R$[$rs$]+$ R$[$rt$)$

This is a new version of add that result is written in the memory. for example, add $0($Sto$),$st$1,5$t$2.$ if Sto$=1000,$ Sti$=5$ and St$2=12$ then $5+12-17$ is saved in memory location $(1000+0)$

Which new functional blocks $($if any$)$ do we need for this instruction? Justify