#include<iostream>
#include<string>
using namespace std;
class Tree {
public:
Tree(char value) {
val = value;
}
char val;
Tree* leftTree = NULL;
Tree* rightTree = NULL;
};
Tree* GetBinnaryTree(string preorder, string midorder) {
if (preorder.size() == 0 || midorder.size() == 0) {
return NULL;
}
char value = preorder[0];
Tree* root = new Tree(value);
int index = 0;
while (midorder[index] != value) {
index++;
}
string left_midorder = "";
for (int i = 0; i < index; i++) {
left_midorder += midorder[i];
}
string right_midorder = "";
for (int i = index + 1; i < midorder.size(); i++) {
right_midorder += midorder[i];
}
string left_preorder = "";
for (int i = 1; i <= left_midorder.size(); i++) {
left_preorder += preorder[i];
}
string right_preorder = "";
for (int i = left_midorder.size() + 1; i < preorder.size(); i++) {
right_preorder += preorder[i];
}
root->leftTree = GetBinnaryTree(left_preorder, left_midorder);
root->rightTree = GetBinnaryTree(right_preorder, right_midorder);
return root;
}
void nextorder(Tree* root) {
if (root == NULL) {
return;
}
nextorder(root->leftTree);
nextorder(root->rightTree);
cout << root->val;
}
int main() {
while (true) {
string preorder, midorder;
cin >> preorder >> midorder;
Tree* root = GetBinnaryTree(preorder, midorder);
nextorder(root);
cout << endl;
}
return 0;
}