diff --git a/du6/program.c b/du6/program.c
index 23c07be..4f5eb4d 100644
--- a/du6/program.c
+++ b/du6/program.c
@@ -79,6 +79,7 @@ void run_system(Tree *node) {
 
     // list -> koniec
     if (!node->left && !node->right) {
+	printf("Koniec\n")
         return;
     }