On a pull-up bar, do the max number of pull-ups you can (choose a variation that allows at least 10), immediately after reaching max, hang from the bar as long as possible. Once you fall, rest 20 seconds and hang again. Repeat the full cycle 2 more times.
For an advanced challenge try it on a wall and sub climb-ups for pull-ups
Finish with 3 45 second plank holds on the fingertips if possible, on the hands if not.