diff --git a/treap.hpp b/treap.hpp
index 98c287a..2f14e46 100644
--- a/treap.hpp
+++ b/treap.hpp
@@ -109,4 +109,7 @@ public:
 		two.first = split(two.first, k).first;
 		root = join(two);
 	}
+	count_type size() {
+		return get_size(root);
+	}
 };