diff --git a/a1/program.c b/a1/program.c
new file mode 100644
index 0000000..53c5fdf
--- /dev/null
+++ b/a1/program.c
@@ -0,0 +1 @@
+#include <stdio.h>
diff --git a/du1 b/du1
new file mode 160000
index 0000000..1b08a15
--- /dev/null
+++ b/du1
@@ -0,0 +1 @@
+Subproject commit 1b08a156a467b65cacea21d52ea67523c9858e0d