# Definition for a binary tree node.

# class TreeNode(object):

#     def __init__(self, x):

#         self.val = x

#         self.left = None

#         self.right = None

class Solution(object):

    def rightSideView(self, root):

        """

        :type root: TreeNode

        :rtype: List[int]

        """

        def right(level):

            if len(level) == 0:

                return []

            return [level[-1].val]+right([x for i in level for x in [i.left,i.right] if x])

        if not root:

            return []

        return right([root])