Handstand walk 100 meters
If you fall, restart at the point of contact furthest from the finish.
Today if you can handstand walk you are a RX. Chip away at this until you get the required distance.
A couple of ideas if you are not able to handstand walk:
1. If you lack the strength to handstand walk, do 100 handstand pushups, concentrating on a hollow body.
2. Kick up to a wall lift one hand and tap your chest. Count one step for every tap
3. Wheelbarrow walk the required distance
4. Handstand holds, on a wall or freestanding, as much time as you can accumulate in 10 minutes.