#include <bits/stdc++.h>

using namespace std;

struct node

{

    char elem;

    node* l;

    node* r;

};

node* dfs(char* pre,char* in,int len)  //前序首地址、中序首地址、整个数组对应的长度

{

    int i;

    if(len==)

        return NULL;

    node* =new node;

    s->elem=*(pre);

    for(i=; i<len; i++)

        if(in[i]==*(pre))

            break;

    //cout<<s->elem; 前序

    s->l=dfs(pre+,in,i);

    //cout<<s->elem; 中序

    s->r=dfs(pre++i,in+i+,len--i);

    cout<<s->elem; //后序

    return s;

}

int main()

{

    char s1[],s2[];

    while(~scanf("%s",s1))

    {

        cin>>s2;

        int len=strlen(s1);

        node* s=dfs(s1,s2,len);

        cout<<endl;

    }

    return ;

}

#include <bits/stdc++.h>

using namespace std;

struct node

{

    char elem;

    node* l;

    node* r;

};

node* dfs(char* in,char* post,int len)

{

    if(len == ) return NULL;

    node *s = (node *)malloc(sizeof(node));

    s->elem = *(post+len-);

    int i;

    for(i=len-; i>=; i--)

    {

        if(in[i] == s->elem)

            break;

    }

    printf("%c", s->elem);

    s->l = dfs(in, post, i);

    s->r = dfs(in+i+, post+i, len--i);

    return s;

}

int main()

{

    char s1[],s2[];

    while(~scanf("%s",s1))

    {

        cin>>s2;

        int len=strlen(s1);

        node* s=dfs(s1,s2,len);

        cout<<endl;

    }

    return ;

}