```
\documentclass{article}
\usepackage{pdfpages}

\begin{document}
\includepdf[pages=-]{file1.pdf}
\includepdf[pages=-]{file2.pdf}
\end{document}
```
\documentclass{article}
\usepackage{pdfpages}

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