\documentclass[a4paper,9pt]{scrartcl}

% General information.
\newcommand{\teamname}{Hello KITty}
\newcommand{\university}{Karlsruhe Institute of Technology}

% Font encoding.
\usepackage[T1]{fontenc}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}

% Include headers.  
\input{latexHeaders/layout}
\input{latexHeaders/math}
\input{latexHeaders/listings}

% Title and author information.
\title{Team Contest Reference}
\author{\teamname \\ \university}
\date{26. November 2017}
\begin{document}

% Titlepage with table of contents.
\maketitle
\setlength{\columnsep}{1cm}
% \begin{multicols}{2}
% 	\tableofcontents
% \end{multicols}
% \newpage

% Content.
\begin{multicols*}{2}
  \input{datastructures/datastructures}
  \input{graph/graph}
  \input{geometry/geometry}
  \input{math/math}
  \input{string/string}
  \input{other/other}
\end{multicols*}
\end{document}