A regular expression for an automaton which accepts strings with no more than 3 consecutive zeros This is the automaton I want to find the regular expression for:


As you see, states Q1 to Q4 are accepted and Q5 is a kind of trap. This automaton accepts strings that have no more than 3 consecutive zeros.
Can anybody help finding a regular expression for this? 

Note : What I tried ...
I defined A:=(0+00+000)
So the automata accepts the strings which contain no consecutive A's. But I don't know how to find that kind of regular expression.
Hint: A string with no more than 3 consecutive zeroes has the general form
$$0^{p_1} 1 0^{p_2} 1 0^{p_3} 1 \ldots,$$
where $p_i \leq 3$. Try expressing that structure as a regular expression.