Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to hack gmail [title] Understand the limitations. [step] Gmail is an incredibly secure service. The only way you'll be able to " hack " into someone's account is by stealing their password.

Ending1: You will need to make sure that you actually have a password that is valid, or that could slip from someone's system. To be successful, you must be able to, or at least to know. Ending2: If your target has two-factor authentication, you'll need their mobile device as well. There is no other way around two-factor authentication. Ending3: [substeps] You must be a " good " user to hack a gmail account. This means to use this service only online. Ending4: To hack someone's password, simply click the " hack " button beside the user name. Once prompted, enter your password, then click " confirm.

Answer format: ending1/ending2/ending3/ending4