diff --git a/build.sh b/build.sh
index 2333e3a..7a02b0c 100755
--- a/build.sh
+++ b/build.sh
@@ -3,14 +3,18 @@ FILE="$(realpath "${BASH_SOURCE[0]}")"
 ROOT="$(dirname "${FILE}")"
 
 INPUT="${ROOT}/in"
+INPUTS="${ROOT}/in.txt"
 OUTPUT="${ROOT}/out"
 
+function main {
+local file
+local files=()
+
 rm --force --recursive "${OUTPUT}"
 mkdir --parents "${OUTPUT}"
 
-FILES=()
-for f in $(cat "${ROOT}/in.txt") ; do
-    FILES+=("${INPUT}/${f}.md")
+for file in $(cat "${INPUTS}") ; do
+    files+=("${INPUT}/${f}.md")
 done
 
 pandoc \
@@ -27,4 +31,8 @@ pandoc \
 --variable revealjs-url='/sw/revealjs/up' \
 --variable slideNumber \
 \
-"${FILES[@]}"
+"${files[@]}"
+
+}
+
+main