#include <fstream>
using namespace std;
char inorder[27];
int size;
char preorder[27];
int mapx[26];//map
class node
{
public:
	node()
	{
		left = NULL;
		right = NULL;
	}
	char c;
	node* left;
	node* right;

};
void postorder(node*);
int ipost;
char post[27];
node* maketree(int ,int);

int main()
{

	ifstream fin("heritage.in");
	ofstream fout("heritage.out");
	char c;
	bool second = false;
	int size2 = 0;
	while ( (c = fin.get())!=EOF )
	{
		if (c=='\n')
		{
			second = true;
			continue;
		}
		if (!second)
		{
			inorder[size++] = c;
		}
		else
		{
			preorder[size2++] = c;
		}

	}
	//map the in-order to the index it occurs
	for (int i = 0 ; i<size ;i++)
	{
		mapx[inorder[i]-'A'] = i;

	}
	//make tree
	node* root  = maketree(0,size-1);

	//post-order
	postorder(root);
	post[ipost] = NULL;
	fout<<post;
	fout<<endl;

	fin.close();
	fout.close();
	return 0;
}


void postorder(node* root)
{

	if (!root)
		return;
	postorder(root->left);
	postorder(root->right);
	post[ipost++]=root->c;
}


int ppos;
node* maketree(int begin ,int end)
{
	if (ppos==size)
		return NULL;

	char c = preorder[ppos++];
	if (begin==end&&begin==mapx[c-'A'])
	{
		node* single = new node();
		single->c  = c;
		return single;
	}
	else if (mapx[c-'A']>=begin&&mapx[c-'A']<=end)
	{
		node* root = new node();
		root->c = c;
		root->left = maketree(begin,mapx[c-'A']-1);

		root->right = maketree(mapx[c-'A']+1,end);
		return root;
	}
	else
	{
		ppos--;
		return NULL;
	}
}