\documentclass{article}
% This comment should be removed
\usepackage{amsmath}

% TODO: add abstract section
\begin{document}

\title{Test Document}
\maketitle

% This comment should also be removed
The probability is 50\% of the total.
In math mode: $x = a \% b$ is valid.

\begin{equation}
  E = mc^2
\end{equation}

\end{document}
