documentclass[12pt,a4paper]{scrartcl}
usepackage[T1]{fontenc}
usepackage[ngerman]{babel}
usepackage{float}
usepackage[utf8]{inputenc}
usepackage{subfigure}
usepackage[pdftex]{graphicx}
usepackage{latexsym}
usepackage{amsmath,amssymb,amsthm}
usepackage{listings}
usepackage{geometry}

usepackage{tikz}

usepackage{xcolor}