diff --git a/cv7/program.c b/cv7/program.c
index 0cd8271..8abb815 100644
--- a/cv7/program.c
+++ b/cv7/program.c
@@ -34,6 +34,12 @@ struct tree* read_tree(int* counter) {
     }
     tree->left = read_tree(counter);
     tree->right = read_tree(counter);
+    if ((tree->left == NULL) != (tree->right == NULL)) {
+        printf("Chybna databaza\n");
+        free(tree->value);
+        free(tree);
+        exit(1);
+    }
     return tree;
 }