Please choose the correct ending to complete the given sentence: Cars & Other Vehicles: [header] How to stretch after a long flight [title] Perform neck rolls during the flight. [step] Neck rolls are a simple exercise that you can do periodically throughout the flight while sitting in your seat. This exercise will stretch your neck and keep it from getting stiff.

Ending1: [substeps] Move your head up and down and side to side slowly, making a " yes " movement followed by a " no " movement. After a few slow movements, lean your head sideways, trying to touch your ear to your shoulder. Ending2: [substeps] Hold one hand (palm facing up) in front of you. Then, slowly roll one of your hands back to the other side of your head. Ending3: [substeps] Lie on the floor with a pillow under your head. Place a pair of hands on either side of your head. Ending4: [substeps] To do neck rolls, stand up with your feet shoulder width apart and put your hands in front of you. Keep your upper back bent and your pelvis as flat as possible.

Answer format: ending1/ending2/ending3/ending4