\documentclass[12pt]{article}
\usepackage{thithongkegiangday}
\usepackage[usestackEOL]{stackengine}
\usepackage{pdflscape}
\usepackage{rotating}
\usepackage{ifxetex}
\ifxetex
\usepackage{xltxtra}
\else
\usepackage[utf8]{vntex}
\usepackage{lmodern}
\usepackage{charter}
\fi
\usepackage[
top=0.75cm,
bottom=0.75cm,
left=0.75cm,
right=0.75cm,
footskip=0.25cm,
a4paper
]{geometry}
\pagestyle{empty}
\mauchu{blue}
\begin{document}
\thongkegiangday
\bangtonghop
\end{document}
