diff --git a/du6/program.c b/du6/program.c
index ee11edb..c540d99 100644
--- a/du6/program.c
+++ b/du6/program.c
@@ -12,7 +12,7 @@ typedef struct TreeNode {
 
 static TreeNode* read_tree_node() {
     char buffer[MAXLINE];
-    memset(buffer, 0, sizeof(buffer));
+    memset(buffer, 1, sizeof(buffer));
 
     char *r = fgets(buffer, sizeof(buffer), stdin);
     if (r == NULL) {