# How to say if this grammar is LL(1)?

I need some help with understanding if a grammar is $$LL(1)$$ or not.

\begin{align} S \rightarrow AB\ A \rightarrow a \mid \varepsilon \ B \rightarrow bCd\ C \rightarrow c \mid \varepsilon \end{align}

I have computed the first and follow sets and I’ve tried to use $$LL(1)$$ definition, but I don’t know how to answer it.