diff --git a/day18.py b/day18.py
index 2f97f7e..602c75b 100644
--- a/day18.py
+++ b/day18.py
@@ -115,8 +115,21 @@ class BinarySnailfish:
         return root
 
     def getLeftNumber(self) -> Union[None, 'BinarySnailfish']:
+        parent = self.parent
+        if self == self.parent.left:
+            while parent.parent and parent == parent.parent.left:
+                parent = parent.parent
+            parent = parent.left
+        else:
+            while parent.parent and parent == parent.parent.right:
+                parent = parent.parent
+            parent = parent.right
+        while parent.right.value is None:
+            parent = parent.right
+        return parent
+
         leftnum = None
-        for current in self.getRoot().traverse_inorder():
+        for current in self.getRoot().traverse_preorder():
             if current == self:
                 return leftnum
             if current.value is not None:
@@ -124,7 +137,7 @@ class BinarySnailfish:
 
     def getRightNumber(self) -> Union[None, 'BinarySnailfish']:
         returnNext = 0
-        for current in self.getRoot().traverse_inorder():
+        for current in self.getRoot().traverse_preorder():
             if returnNext >= 3 and current.value is not None:
                 return current
             if returnNext > 0:
@@ -150,36 +163,35 @@ class BinarySnailfish:
         self.value = 0
 
     def reduce(self):
-        print(self.fours)
         if self.value is not None:
             return
         found = True
         while found:
             found = False
-            for n in self.fours:
-                self.fours.pop(0)
-                n.explode()
-                found = True
-                break
+            for n in self.traverse_preorder():
+                if n.value is None and n.depth == 4:
+                    n.explode()
+                    found = True
+                    break
 
             if found:
                 continue
 
-            for n in self.traverse_inorder():
+            for n in self.traverse_preorder():
                 if n.value is not None and n.value > 9:
                     n.split()
                     found = True
                     break
 
-    def traverse_inorder(self):
+    def traverse_preorder(self):
         yield self
 
         if self.left:
-            for x in self.left.traverse_inorder():
+            for x in self.left.traverse_preorder():
                 yield x
 
         if self.right:
-            for x in self.right.traverse_inorder():
+            for x in self.right.traverse_preorder():
                 yield x
 
     def __add__(self, other):