\documentclass[xcolor=dvipsnames]{beamer}
\usepackage{pgfpages}
\usecolortheme[named=NavyBlue]{structure}
\usefonttheme{serif}
\setbeameroption{hide notes}

% \includeonlyframes{c1,c2,c3,c4,c5,c6,c7,c8,c9}
\usepackage{dcolumn}
\newcolumntype{.}{D{.}{.}{-1}}
\newcolumntype{d}[1]{D{.}{.}{#1}}
% \usepackage{wcolor}
\usepackage{color}
% \usepackage[usenames]{color}
\usepackage{wasysym}
\usepackage{graphicx} % psfrag,epsf}
% \usepackage{epsfig}
% math serif font
\usepackage{mathptmx}
% \usepackage{amsfonts}
% \usepackage{amsmath}
% === to strikeout text ===

\usetheme{Madrid} 
% Enable appendix frames not to be in displayed frame denominator
\newcounter{mylastframe}

\title{Title under Title page}
\author[Authors 1/2]{Author 1 \and Author 2}
% \thanks{With special thanks to .}}
\institute[My University]{My University}
\date{\today}
\begin{document}

\begin{frame}
\title{Real Title}
  \titlepage
\end{frame}

\author{My Name}
\institute{My Uni}
\title{Title under Body frames}

\section{Introduction}

\frame{
\frametitle{Sample Slide}
\framesubtitle{}

}

\frame{
\setcounter{mylastframe}{\value{framenumber}}
\frametitle{Last Numbered Frame}
\framesubtitle{}

}

\section{Extra Frames}

\frame{
\frametitle{Extra Frame, Unnumbered}



}

% All appendix frame numbers are ``lastframe''
\setcounter{framenumber}{\value{mylastframe}}

\end{document}
