#include<bits/stdc++.h>
using namespace std;
int main(){
	string s1,s2,s3,cs;
	cin>>s1>>s2;
	s3=s1+s2;
	 for(int i=0;i<s3.size();i++){
	 	if(cs.find(s3[i])==-1){
	 	  cs=cs+s3[i];
	 	}
	 	
	 	
	 }
	 cout<<cs;

	return 0;
}

/**************************************************************
	Problem: 1105
	User: huxuanchen
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2076 kb
****************************************************************/