\documentclass[final,unknownkeysallowed]{beamer}
  \mode<presentation>
  {
% you can chose your theme here:
%  \usetheme{Aachen}
  \usetheme{I6dv}
%  \usetheme{I6pd}
%      \usetheme{Berlin}
%  \usetheme{I6pd2}
%  \usetheme{I6td}
%  \usetheme{Oldi6}
}
\graphicspath{{figures/}}
\usepackage{times}
\usepackage{amsmath,amssymb}
\usepackage[english]{babel}
\usepackage[latin1]{inputenc}
\usepackage[orientation=landscape,size=custom,width=200,height=120,scale=2,debug]{beamerposter}  % e.g. custom size poster
  \title[Fancy Posters]{Making Really Fancy Posters with \LaTeX}
  \author[Dreuw \& Deselaers]{Philippe Dreuw and Thomas Deselaers}
  \institute[RWTH Aachen University]{Human Language Technology and Pattern Recognition,RWTH Aachen University}
  \date{Jul. 31th, 2007}
  \begin{document}
  \begin{frame}{} 
    \vfill
    \begin{block}{\large Fontsizes}
      \centering
      {\tiny tiny}\par
      {\scriptsize scriptsize}\par
      {\footnotesize footnotesize}\par
      {\normalsize normalsize}\par
      {\large large}\par
      {\Large Large}\par
      {\LARGE LARGE}\par
      {\veryHuge veryHuge}\par
      {\VeryHuge VeryHuge}\par
      {\VERYHuge VERYHuge}\par
    \end{block}
    \vfill
    \begin{columns}[t]
      \begin{column}{.48\linewidth}
        \begin{block}{Introduction}
          \begin{itemize}
          \item some items
          \item some items
          \item some items
          \item some items
          \end{itemize}
        \end{block}
      \end{column}
      \begin{column}{.48\linewidth}
        \begin{block}{Introduction}
          \begin{itemize}
          \item some items and $\alpha=\gamma, \sum_{i}$
          \item some items
          \item some items
          \item some items
          \end{itemize}
          $$\alpha=\gamma, \sum_{i}$$
        \end{block}
        \begin{block}{Introduction}
          \begin{itemize}
          \item some items
          \item some items
          \item some items
          \item some items
          \end{itemize}
        \end{block}
        \begin{block}{Introduction}
          \begin{itemize}
          \item some items and $\alpha=\gamma, \sum_{i}$
          \item some items
          \item some items
          \item some items
          \end{itemize}
          $$\alpha=\gamma, \sum_{i}$$
        \end{block}
      \end{column}
    \end{columns}
  \end{frame}
  \end{document}
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