\documentclass[11pt]{article}
\usepackage[margin=1in]{geometry}
\usepackage{xcolor}
\usepackage{mdframed}
\usepackage{amsmath}

% copy cs555_hw_template.tex to cs555_hw_1_1.tex
\newcommand{\yourname}{Your Name}
\newcommand{\yournetid}{yournetid}
\newcommand{\hwnum}{1}
\newcommand{\probnum}{1}

\newenvironment{problem}[2][Problem]
    { \begin{mdframed}[backgroundcolor=gray!20] \textbf{#1 #2} \\}
    {  \end{mdframed}}

\newenvironment{solution}
    {\textit{Solution:}}
    {}

\begin{document}
\noindent
\noindent\rule{\linewidth}{2pt}
\large\textbf{\yourname} \hfill \textbf{CS 555: Homework \# \hwnum}   \\
Email: \yournetid@illinois.edu \hfill Spring 2026\\
\noindent\rule{\linewidth}{2pt}

\begin{problem}{\probnum}
\textcolor{red}{optional: summarize the problem} % TODO
\end{problem}

\begin{solution}
% TODO
\end{solution} 

\end{document}