\documentclass[10pt,a4paper]{article}
\usepackage[paper=a4paper,width=15.5cm,height=20.5cm,top=3cm,left=3cm]{geometry}
\newcommand{\authorinfo}[3][]{\par\noindent\textbf{#2} (\texttt{#1})\par\noindent\textsf{#3}\\\medskip}
\newcommand{\talktitle}[2][]{\title{#2}\author{#1}\date{}\maketitle}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{amssymb,amsthm,amsmath, amsfonts, mathtools,latexsym}

%%%%%  PLEASE, THIS TEMPLATE MUST HAVE TWO PAGES AT MOST  %%%%%%%%%%%%


\begin{document}

%Insert your name and the title of your talk here
\talktitle{XXXXX}

% Fill the author information here and add more if necessary

\authorinfo[email]{Full Name}{Institution}

\noindent\textbf{Abstract}. % Write your abstract here



\end{document} 

