\include{preamble}

\title{Cactus Demonstation}
\author{The Cactus team}
\date{\today}

\begin{document}

\frame{\titlepage}

\section[Outline]{}
\frame{\tableofcontents}

\section{Introduction}
\subsection{Whatever}

\section{blafasel}
\subsection{blub}
\include{cactus_structure_overview}

\end{document}