diff --git a/u8/program.py b/u8/program.py
index 1648a46..61deab4 100644
--- a/u8/program.py
+++ b/u8/program.py
@@ -8,6 +8,9 @@ def main():
     q = pocet_otazok(tree_lines)
     a = pocet_odpovedi(tree_lines)
     tree = build_tree(tree_lines)
+    if tree is None or len(tree) == 0:
+        print("Chybna databaza")
+        return
     print("Pocet otazok:", q)
     print("Pocet odpovedi:", a)
     print("Odpovedajte 'a' pre prvu moznost alebo 'n' pre druhu moznost.")