#include <stdio.h>
#include <string.h>
char nlr[27];
char lnr[27];
void lrn(int nlr_start,int nlr_end,int lnr_start,int lnr_end)
{
    if(nlr_start>nlr_end)return;
    char root=nlr[nlr_start];
    int index=-1;
    for(int i=lnr_start;i<=lnr_end;i++)
    {
        if(root==lnr[i])
        {
            index=i;
            break;
        }
    }
    lrn(nlr_start+1,index+nlr_start-lnr_start,lnr_start,index-1);
    lrn(index+nlr_start-lnr_start+1,nlr_end,index+1,lnr_end);
    printf("%c",root);
}
int main() {

    while (scanf("%s %s", &nlr[0], &lnr[0]) != EOF) { // 注意 while 处理多个 case
        lrn(0,strlen(nlr)-1,0,strlen(lnr)-1);
        printf("\n");
    }
    return 0;
}