#include<iostream>
#include<cstring>
using namespace std;
const int maxn = 100;
typedef struct BitNode{
 char Data;
 struct BitNode *Lchild,*rchild;
}BitNode,*Bittree;

char preArray[maxn];
char InArray[maxn];
void Createtree(Bittree &T, int prS, int prE, int inS, int inE)
{
    T = (Bittree)malloc(sizeof(BitNode));
    int Root;
    T ->Data = preArray[prS];
    for (int i = inS; i <= inE; i++)
    {
        if(T ->Data == InArray[i])
        {
            Root = i;
            break;
        }
    }
    if(Root != inS)
    {
        Createtree(T->Lchild,prS + 1,(Root - inS) + prS, inS, Root - 1);
    }
    else{
        T->Lchild = NULL;
    }

    if(Root != inE)
    {
        Createtree(T->rchild,(Root - inS) + prS+1,prE,Root + 1,inE);
    }
    else{
        T->rchild = NULL;
    }
}
void printorder(Bittree T)
{
    if(T->Lchild !=NULL)
    {
        printorder(T->Lchild);
    }
    if(T->rchild !=NULL)
    {
         printorder(T->rchild);
    }
    printf("%c",T->Data);
}
int main()
{
    while(scanf("%s", preArray) != EOF)
    {
        Bittree T;
        scanf("%s", InArray);
        Createtree(T,0,strlen(preArray) - 1,0,strlen(InArray) - 1);
        printorder(T);
        cout << endl;
    }
}