Here is my code:
\documentclass{cimento}
\usepackage[utf8]{inputenc}
\usepackage{graphicx}
\title{Higgs studies}
\author{Higgs}
\instlist{\XXXX University}
\begin{document}
XXXXXXXXXXXXXXXXXXXXXXXx
\end{document}
The error I got is:
! LaTeX Error: File `cimento.cls' not found.
Type X to quit or <RETURN> to proceed,
or enter new name. (Default extension: cls)
Enter file name:
Anyone could you please let me know what I should do to solve this problem?

