\documentclass[
    12pt,
    DIV=10,
    BCOR=0mm,
    twoside=true,
    chapterprefix=true,
    headinclude=true,
    footinclude=true,
    usegeometry=true,
    headings=big]{skript}
\usepackage[top=2cm,bottom=2cm]{geometry}
\input{common.tex}