My

\documentclass[a4paper]{article}
\usepackage[a4paper,margin=2cm]{geometry} 
\usepackage{xeCJK,enumitem,titlesec,graphicx,listings,amsmath}
\setCJKmainfont{Noto Sans CJK TC}

\titleformat{\section}[block]{}{{\bfseries Problem} \thesection.}{1em}{}{}
\titleformat{\subsection}[block]{}{\thesubsection}{10pt}{}{}
\titleformat{\subsubsection}[block]{\hspace{1em}}{(\alph{subsubsection})}{10pt}{}{}

\setlength{\leftmargin}{10cm}
\lstset{
    numbers=left,
    breaklines=true,
    tabsize=4,
    basicstyle=\ttfamily,
    showstringspaces=false
}

\title{\textbf{Homework}}
\author{B05902094 蘇多門}
\date{}

\begin{document}

\maketitle

\section{Example Problem}
\subsection{subproblem test}
\subsubsection{subsubproblem}
\begin{lstlisting}[language=Python]
for i in range(10):
	print("example code %d"%i)
\end{lstlisting}

\end{document}