Error in using package “mwe” in Latex

Question

I am trying to run the following code in Latex, but it gives me this error:

! LaTeX Error: File `mwe.sty' not found.

Code:

\documentclass{article}
\usepackage{mwe}
\usepackage{subfig}
\begin{document}
\begin{figure}
\begin{minipage}
\centering
\subfloat[]{\label{main:a}\includegraphics[scale=.5]{plot1.eps}}
\end{minipage}%
\begin{minipage}
\centering
\subfloat[]{\label{main:b}\includegraphics[scale=.5]{plot2.eps}}
\end{minipage}\par\medskip
\centering
\subfloat[]{\label{main:c}\includegraphics[scale=.5]{plot3.eps}}
\caption{my fig}
\label{fig:main}
\end{figure}
\end{document}