Cast Sensei's Divining Top by paying ({1} magic symbol) .
Forensic Gadgeteer and Birgi trigger.
Resolve the Birgi trigger, adding ({R} magic symbol) .
Resolve the Forensic Gadgeteer trigger, creating a Clue token.
Activate Urza's first ability by tapping the Clue, adding ({U} magic symbol) .
Activate Sensei's Divining Top's second ability by tapping it, causing you to draw a card and put Sensei's Divining Top from the battlefield on top of your library.
Activate the Clue by paying ({1} magic symbol) and sacrificing it, causing you to draw Sensei's Divining Top from the top of your library.