#include<cstdio>
#include<cstring>
using namespace std;
/*根据二叉树的先序遍历和中序遍历求后序遍历
*利用先序是根->左->右,而中序是左->根->右
*找出根的位置,划分左右子树,在递归求解
*/
char pre[35],in[35];
void print_Btree(int len,char *pre,char *in)
{
if(len<=0)
return;
int pos = strchr(in,pre[0])-in;
print_Btree(pos,pre+1,in);
print_Btree(len-pos-1,pre+pos+1,in+pos+1);
printf("%c",pre[0]);
}
int main()
{
int len;
while(~scanf("%s %s",pre,in))
{
len = strlen(pre);
print_Btree(len,pre,in);
printf("\n");
memset(pre,0,sizeof(pre));
memset(in,0,sizeof(in));
}
return 0;
}