Logo HelloWorld信息学奥赛题库

少儿编程

时间限制:1 s 空间限制:256 MB

#13045. American Heritage

Statistics

题目描述

Farmer John takes the heritage of his cows very seriously. He is not, however, a truly fine bookkeeper. He keeps his cow genealogies as binary trees and, instead of writing them in graphic form, he records them in the more linear `tree in-order' and `tree pre-order' notations.

Your job is to create the `tree post-order' notation of a cow's heritage after being given the in-order and pre-order notations. Each cow name is encoded as a unique letter. (You may already know that you can frequently reconstruct a tree from any two of the ordered traversals.) Obviously, the trees will have no more than 26 nodes.

Here is a graphical representation of the tree used in the sample input and output:

                  C
                /   \
               /     \
              B       G
             / \     /
            A   D   H
               / \
              E   F
The in-order traversal of this tree prints the left sub-tree, the root, and the right sub-tree.

The pre-order traversal of this tree prints the root, the left sub-tree, and the right sub-tree.

The post-order traversal of this tree print the left sub-tree, the right sub-tree, and the root.

输入格式

Line 1:    The in-order representation of a tree.
Line 2:    The pre-order representation of that same tree.

输出格式

A single line with the post-order representation of the tree.

样例数据

input

ABEDFCHG
CBADEFGH

output

AEFDBHGC