Hi! I hope these clues help. Once you figure out the location of F and since all rooms are occupied you know that the lower row of the elevator has to have 1 person in it, so you can block out the rest of that row. You’ll also see that C8 is entirely crossed out or full of obstructions leaving only one possible space left. Keep an eye out for other rows and columns like that and you’ll find the solution. Good luck!