diff --git a/llo-index.yml b/llo-index.yml
index b07b12f..872e227 100644
--- a/llo-index.yml
+++ b/llo-index.yml
@@ -16,11 +16,15 @@
       mimetype: "text/x-python"
     code:
       subdir: ""
-      lang: "c"
+      lang: "gcc"
       version: "2"
-      file: "squares.c"
-      options: ""
+      file: "helloworld.c"
+      options: "-Wall"
       mimetype: "text/plain"
+      output: "yes"
+        file: ""
+        options: ""
+        mimetype: "text/img"
     challenge:
       subdir: ""
       question: "q-info.sh"
@@ -28,6 +32,10 @@
       codeanswer: "codeanswer.sh"
       points: "1" # ELO
       mimetype: "text/x-python"
+      output: "yes"
+        file: ""
+        options: ""
+        mimetype: "image"
   llospec1:
     display_name: "title1"
     dir: "net1"
diff --git a/swarmlab/llo/helloworld.c b/swarmlab/llo/helloworld.c
new file mode 100644
index 0000000..020484e
--- /dev/null
+++ b/swarmlab/llo/helloworld.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+main (void)
+{
+  printf ("Hello, world!\n");
+  return 0;
+}