A classic benchmark, Cindy is a great test of body-weight strength and metabolic conditioning. Scales for pull-ups may include using bands or doing ring rows, or you might want to do a harder pull-up progression and do rounds of 3/6/9 or 4/8/12. The idea of these progressions is to keep you moving as much as possible and not let muscle fatigue set in too quickly.
AMRAP in 20 minutes:
15 air squats