diff --git a/labs/10_trees_I/test_ds_set.cpp b/labs/10_trees_I/test_ds_set.cpp
index 02f7b9f..95867c9 100644
--- a/labs/10_trees_I/test_ds_set.cpp
+++ b/labs/10_trees_I/test_ds_set.cpp
@@ -88,6 +88,7 @@ int main() {
   assert(insert_result.second);
   std::cout << "\nAfter two inserts:\n"
 	    << "set1.size() = " << set1.size() << ", set2.size() = " << set2.size() << "\n"
+	    << "\nThe contents of set1:\n" << set1 << std::endl;
 	    << "\nThe contents of set2:\n" << set2 << std::endl;
 
   */