Find all hazards in this instruction sequence for a $5-$stage pipeline with and

then without forwarding.

Hint: Please fill in the gray box with an answer like $"($$$1)$ I$1$ to I$3".$ Please find all

the hazards. In addition, not every gray box needs to be filled in$.$

I$1$: lw $$1,40($$$2)$

I$2$: add $$2,$ $$3,$ $$3$

I$3$: add $$1,$ $$1,$ $$2$

I$4$: sw $$1,20($$$2)$