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#include <bits/stdc++.h>
using namespace std;

typedef struct node {
	char data;
	node *lchild, *rchild;
} tree, *treelink;

void Create_tree(treelink &t, string pre, string in) {
	if (pre.size() == 0) {
		t = NULL;
		return ;
	}
	char root = pre[0];
	int index = in.find(root);
	string left_in = in.substr(0, index);
	string right_in = in.substr(index + 1);
	int len_left = left_in.size();
	int len_right = right_in.length();
	string left_pre = pre.substr(1, len_left);
	string right_pre = pre.substr(len_left + 1);
	t = new tree;
	t->data = root;
	Create_tree(t->lchild, left_pre, left_in);
	Create_tree(t->rchild, right_pre, right_in);
}

void last(treelink t) {
	if (t != NULL) {
		last(t->lchild);
		last(t->rchild);
		cout << t->data;
	}
}

int main() {
	string pre, in;
	cin >> pre >> in;
	treelink t;
	Create_tree(t, pre, in);
	last(t);
	return 0;
}