```
class Solution:
# @param root, a tree node
# @return an integer
def sumNumbers(self, root):
if root is None:
return 0
res = self.sumNum(root,0)
return res
def sumNum(self, root, mid_res):
if root is None:
return mid_res
mid_res += root.val
left = root.left
right = root.right
if left is None and right is None:
return mid_res
if left is not None and right is None:
res = self.sumNum(left,mid_res*10)
return res
if right is not None and left is None:
res = self.sumNum(right,mid_res*10)
return res
res = self.sumNum(left,mid_res*10) + self.sumNum(right,mid_res*10)
return res
```