Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to exercise in bed [title] Do push-ups. [step] Push-ups are a classic exercise that can increase arm strength. You can also easily do them from your bed.

Ending1: Sit in the same position as you would if you were in bed; as long as your back doesn't hurt, and your feet are comfortably on the floor, you're good to do push-ups. [substeps] To do a push-up, lie on your side. Ending2: Reach into your drawer to find and complete three sets of six to 12 reps each. Doing push-ups with the help of a chair or wall can give you access to very useful exercise pieces. Ending3: To do push-ups, stand with your feet shoulder-width apart. Raise your arms above your head and legs up into the air. Ending4: [substeps] Place your knees or toes and your hands on the bed, while keeping your back straight. If you're a beginner, it's a good idea to use your knees over your toes.

Answer format: ending1/ending2/ending3/ending4