\documentclass[aspectratio=169]{beamer}
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\input{package}
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\author{First Author \\Second Author}
\title{Presentation Title}
\subtitle{Presentation Subtitle}
\institute{}
\date{}
\begin{document}
\begin{backgroundblock}{-1.4mm}{0mm}
\includegraphics[width=\paperwidth,height=\paperheight]{background.pdf}
\end{backgroundblock}
\maketitle
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% List of Contents%%%%%%%%%%%%%%%%%%%%%%%%%%%
% To not show in the index, use \section \subsection ...
% To not show in the index just delete the following frame (or comment out the recommended one)
%\section*{List of Contents}
\begin{frame}
\begin{columns}[t]
\begin{column}{.5\textwidth}
\tableofcontents[sectionstyle=show,subsectionstyle=show/shaded/hide,subsubsectionstyle=show/shaded/hide,sections={1-4}]
\end{column}
\begin{column}{.5\textwidth}
\tableofcontents[sectionstyle=show,subsectionstyle=show/shaded/hide,subsubsectionstyle=show/shaded/hide,sections={5-8}]
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\section{Introduction}
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\frametitle{}
%\begin{center}
{\bf Dear author, the organizing committee of OL2A 23 appreciates your contribution.}
\mbox{}\linebreak
\noindent We would like to inform you that the use of this template {\bf is not mandatory.}
\mbox{}\linebreak
\noindent The time that you have available for your presentation {\bf is limited to a maximum of 10 minutes}, with an additional 5 minutes \textbf{exclusively} for questions and answers.
%\end{center}
\end{frame}
\section{Document Structure}
\subsection{Figures}
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\begin{frame}
\frametitle{Include figures}
\begin{figure}[htpb]
\centering
\includegraphics[width=0.4\textwidth]{Figures/lion_large.png}
\caption{Example of a figure.}
\label{fig:lion_large}
\end{figure}
\end{frame}
\subsection{Subfigures}
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\begin{frame}
\frametitle{Include subfigures}
\begin{figure}[h]
\centering
\subfigure[Lion]{ \label{subfig:lion}
\includegraphics[width=0.28\textwidth]{Figures/lion_large.png}
} \ \ \ \ \ \ \
\subfigure[Graphic]{ \label{subfig:graphic}
\includegraphics[width=0.4\textwidth]{Figures/graphic.png}
}
\caption{Figures presented with the \textit{subfigure} package.}
\label{fig:leao_grafico}
\end{figure}
\end{frame}
\subsection{Tables}
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\begin{frame}
\frametitle{Include tables}
\begin{table}[H]
\renewcommand{\arraystretch}{1.15}
\centering
\caption{Tables presented with the \textit{booktabs} package.}
\label{example-table}
\begin{tabular}{llr}
\toprule
\multicolumn{2}{c}{OL2A} \\
\cmidrule(r){1-2}
Column 1 & Column 2 & Column 3\\
\midrule
Line 1 & Line 2 & Line 3 \\
Line 4 & Line 5 & Line 5 \\
\bottomrule
\end{tabular}
\end{table}
\end{frame}
\subsection{Equation}
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\begin{frame}
\frametitle{Include equations}
\begin{equation}
y_1=y_0 + h.f(x_0-y_0)
\end{equation}
\begin{subequations}
\begin{align}
y_{n+1}& = y_{n}+\dfrac{h}{6} \times (k_1 +2k_2 + 2k_3 + k_4)\\
t_{n+1}& = t_n + h
\end{align}
\end{subequations}
\end{frame}
\section{Conclusion}
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\begin{frame}
\begin{center}
\vfill
{\Large \bf Hope to see you at OL2A !}\\
\vfill
\end{center}
\end{frame}
%\section{References}
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% \bibliography{bibliography}
%\bibliographystyle{ieeetr}
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\end{document}