\documentclass[10pt,a5paper,twoside,openright,twocolumn,german]{book}

% encoding
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

% includable git commit info
\usepackage[missing=run\ build.sh\ or\ gitinfohook.sh]{gitinfo}

% page formatting
\usepackage[columnsep=.75cm,lmargin=.75cm,rmargin=.75cm,tmargin=1.5cm,bmargin=1.5cm]{geometry}
\setlength{\parindent}{0pt}

\usepackage{fancyhdr}
\pagestyle{fancy}
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\rhead{}
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\renewcommand{\chaptermark}[1]{ \markboth{#1}{} }
\fancyhead[LE,RO]{\leftmark}
\fancyfoot[LE,RO]{\thepage}

% Use sans serif font.
\renewcommand*{\familydefault}{\sfdefault}

% Fürs "last generated" Datum
\usepackage[iso]{isodate}

% Image import stuff
\usepackage[absolute]{textpos}
\usepackage{graphicx}
\DeclareGraphicsExtensions{.pdf,.png,.jpg}

% \chapter hacks
% Create \Hide command (used for chapters)
\usepackage[explicit]{titlesec}
\newcommand*\Hide{\titleformat{\chapter}[display]{}{}{0pt}{\Huge}\titleformat{\part}{}{}{0pt}{}}

% inhibit creation of new double page on new chapter.
\usepackage{etoolbox}
\makeatletter
\patchcmd{\chapter}{\if@openright\cleardoublepage\else\clearpage\fi}{}{}{}
\makeatother

% make \chapter not use up any space.
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% make \paragraph do newlines
\makeatletter
\renewcommand\paragraph{\@startsection{paragraph}{4}{\z@}%
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  {0.01pt}%
  {\normalfont\normalsize\bfseries}%
}
\makeatother

% inhibit "Contents" Head in TOC
\makeatletter
\renewcommand\tableofcontents{\@starttoc{toc}}
\makeatother

% disable chapter, section, ... numbering
\setcounter{secnumdepth}{-1}

% make footnote numbering reset on every page.
\usepackage[perpage]{footmisc}

% clickable references/links/...
\usepackage{hyperref}

% euro-sign
\usepackage{eurosym}
\DeclareUnicodeCharacter{20AC}{\euro}


% START DOCUMENT
\begin{document}\thispagestyle{empty}
\begin{textblock*}{\paperwidth}(0mm,0mm)\noindent\includegraphics[width=\paperwidth,height=\paperheight]{images/cover_front.png}
\end{textblock*}
\mbox{}\newpage

%hack to have more characters per page.
\small

\twocolumn
\thispagestyle{empty}
\input{articles/_impressum.tex}\newpage
\input{articles/_adressen.tex}
\newpage\thispagestyle{empty}
\input{articles/_editorial.tex}\newpage
\section*{Inhalt}\tableofcontents
\begin{center}\footnotesize{Document (.tex) compiled on: \today\\
This is revision: \gitAbbrevHash}\end{center}

\clearpage\Hide\chapter{Einleitung}\thispagestyle{fancy}
\input{articles/einleitung_die_fsinf.tex}\newpage
\input{articles/einleitung_beratung.tex}\newpage

\clearpage\Hide\chapter{Vor dem Studium}\thispagestyle{fancy}
\input{articles/vor_das_richtige_studium.tex}\newpage
\input{articles/vor_einleitung_bac.tex}\newpage
\input{articles/vor_medieninf.tex}\newpage
\input{articles/vor_medzinf.tex}\newpage
\input{articles/vor_se.tex}\newpage
\input{articles/vor_ti.tex}\newpage
\input{articles/vor_inskription.tex}\newpage
\input{articles/vor_module.tex}\newpage
\input{articles/vor_prolog.tex}\newpage 

\clearpage\Hide\chapter{Erstes Semester}\thispagestyle{fancy}
\input{articles/es_bday.tex}\newpage
\input{articles/es_estuts.tex}\newpage
\input{articles/es_studplan.tex}\newpage
\input{articles/es_lvas.tex}\newpage
\input{articles/es_steop.tex}\newpage
\input{articles/es_ticket.tex}\newpage

\clearpage\Hide\chapter{Unialltag}\thispagestyle{fancy}
\input{articles/unialltag_bibliothek.tex}\newpage
\input{articles/unialltag_lokaltipps.tex}\newpage
\input{articles/unialltag_lernraume.tex}\newpage

\clearpage\Hide\chapter{Uni im Internet}\thispagestyle{fancy}
\input{articles/inet_zid.tex}\newpage
\onecolumn
\input{articles/inet_tiss.tex}\newpage
\twocolumn
\input{articles/inet_fsinf.tex}\newpage
\input{articles/inet_vowi.tex}\newpage
\input{articles/inet_infforum.tex}\newpage

\clearpage\Hide\chapter{Uni für Fortgeschrittene}\thispagestyle{fancy}
\input{articles/advuni_anerkennung.tex}\newpage
\input{articles/advuni_mitbelegen.tex}\newpage
\input{articles/advuni_pruefungsrecht.tex}\newpage
\input{articles/advuni_erasmus.tex}\newpage

\onecolumn
\mbox{}\clearpage\thispagestyle{empty}
\begin{textblock*}{\paperwidth}(0mm,0mm)\noindent\includegraphics[width=\paperwidth,height=\paperheight]{images/cover_back.png}
\end{textblock*}
\end{document}
