\documentclass{beamer}


\title{There Is No Largest Prime Number}
\subtitle{Unfortunately}
\date[ISPN ’80]{27th International Symposium of Prime Numbers}
\author[Euclid]{Alberto Simões}
\institute{albertosimoes@esmad.ipp.pt}
\date{\today}

\usetheme{-esmad}

\begin{document}

\begin{frame}[plain]
\titlepage
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\begin{frame} {There Is No Largest Prime Number}{The proof uses \textit{reductio ad absurdum}.}

\begin{theorem}
There is no largest prime number.
\end{theorem} 

\begin{enumerate} 
\item<1-> Suppose $p$ were the \emph{largest} prime number. 
\item<2-> Let $q$ be the product of the first $p$ numbers. 
\item<3-> Then $q+1$ is not divisible by any of them. 
\item<4-> But $q + 1$ is greater than $1$, thus divisible by some prime
number not in the first $p$ numbers.
\end{enumerate}
\end{frame}

\begin{frame}{A longer title}
\begin{itemize}
\item one
\item two
\end{itemize}
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\end{document}

