Stand straight with your feet a bit wider than your shoulder. You can have either nothing or some boxes in front of you to make exercise a bit easier - having higher boxes will make it easier to pull back.
Start leaning forward till you are falling to the ground. Have your arms in front of you and catch your body with them by doing a push-up.
After making a successful push-up, make explosive push to get your body back into a standing position.
Repeat for required amount of times.