具体的でない方法としては

```
\usepackage[final]{pdfpages}

\begin{document}

\includepdf[pages=-]{file1.pdf}
\includepdf[pages=-]{file2.pdf}

\end{document}
```
a non specific way would be:

\usepackage[final]{pdfpages}

\begin{document}

\includepdf[pages=-]{file1.pdf}
\includepdf[pages=-]{file2.pdf}

\end{document}