diff --git a/.latexmkrc b/.latexmkrc
new file mode 100644
index 0000000..1d6f797
--- /dev/null
+++ b/.latexmkrc
@@ -0,0 +1,2 @@
+# Ensure './texmf//' is in '$TEXINPUTS'.
+ensure_path( 'TEXINPUTS', './texmf//' );
diff --git a/README.md b/README.md
index c53c0e6..449ffcb 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,8 @@ presenter won't need any additional frame or slide environment to split differen
 
 ## Demo
 
+You could compile `main.tex` directly by `latexmk -pdf main` in this repo.
+
 ```diff
 -\documentclass{article}
 +\documentclass{presenter}
diff --git a/main.tex b/main.tex
new file mode 100644
index 0000000..d89380c
--- /dev/null
+++ b/main.tex
@@ -0,0 +1,7 @@
+% Compile this document by:
+%   latexmk -pdf main
+\documentclass{presenter}
+\begin{document}
+\section{Get Started}
+Hello, world!
+\end{document}