Consider the alphabet ? = {a, b}. Give the FAs, either deterministic or nondeterministic, that accept the languages below. Briefly explain the idea underlying each FA.

1. L1 = ??

2. L2 = ?? ? {?}

3. L3 = {w|w ? ? ? and |w| mod 5 = 0}

4. L4 = {w|w contains bbb or aba}