#include<bits/stdc++.h>
using namespace std;
 
string pss, iss;
void func(string pss,string iss){
	if(pss=="" or iss=="") return;
	char ths=pss[0];
	int pvt;
	for(pvt=0; iss[pvt]!=ths; pvt++);
	// 遞迴處理左邊
	func(pss.substr(1,pvt),iss.substr(0,pvt));
	// 遞迴處理右邊
	func(pss.substr(pvt+1,pss.length()),iss.substr(pvt+1,iss.length()));
	// 輸出後序字元
	cout<<ths; 
}
int main(){
	while( cin>>pss>>iss ){
		func(pss,iss);
		cout<<"\n";
	}
}

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

REJBQ0VHRiBBQkNERUZHCkJDQUQgQ0JBRA==

DBACEGF ABCDEFG
BCAD CBAD