I think you are required to have both. What if in some instance, you keep scanning your print but for whatever reason the phone doesn't recognize it? How will you get into your phone? The password is for when the fingerprint doesn't work. Which hopefully never happens, but hey, fingerprint readers aren't always perfect.
Use this opportunity to switch to a complex pass code. Apple should have made that the default on iPhone 5S, but still always a step behind on security.
Use this opportunity to switch to a complex pass code. Apple should have made that the default on iPhone 5S, but still always a step behind on security.