#include<iostream>      
#include<string>
using namespace std;  
int main(){           
   string s1,s2;
   int a[26];
   cin>>s1;
   cin>>s2;
   s1 = s1 + s2;
   for(int i = 0;i <= 25;i++)  
   {
   	  a[i] = 0;
   }
   for(int i = 0;i < s1.length();i++)
   {
   	  if(a[s1[i] - 97] == 0){
   	     cout<<s1[i];	
   	     a[s1[i] - 97] = 1;
	  }
   }
   cout<<endl;
} 

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