\documentclass{amsart}

\newcommand{\pathtotrunk}{../../}
\input{\pathtotrunk text/article_preamble.tex}

\pagestyle{empty}

\begin{document}
\thispagestyle{empty}


$$\underbrace{111111111}$$

$2n+3$ edges

\begin{align*}
f^{(k)} f^{(i)} P S \dots
\end{align*}
\end{document}