1 files changed, 2 insertions, 1 deletions

diff --git a/tree.h b/tree.h
index 48f4de1..2a0bb84 100644
--- a/tree.h
+++ b/tree.h
@@ -1,6 +1,7 @@
 #include <vector>
 #include <string>
-#include <stdlib.h>
+#include <sstream>
+#include <math.h>
 
 using namespace std;