\documentclass{article}
%This is a comment - ignored by LaTeX!

%Allow accented caratexrs (UTF8) and set language to brazilian
\usepackage[utf8x]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[brazilian]{babel}
%....
%More than one author
\usepackage{authblk}

\title{Put Your Title Here}
\author[1]{Alice Smith}
\author[2]{Bob Jones}
\author[3]{Mahatma Gandhi}
\affil[1]{Department of Mathematics, University X}
\affil[2]{Department of Biology, University Y}
\affil[3]{Department of Biology, University Z}


\begin{document}

   \maketitle
   \begin{abstract}
      Very important, ground breaking scientific paper!
      
      Read all about it!
   \end{abstract}

\end{document}
