#include<iostream>
#include<cctype>
#include<string>
using namespace std;
int main(){
string s1,s2,ans;
cin>>s1>>s2;
for(int i=0;i<s1.length();i++){
if(s2.find(s1[i])==string::npos&&ans.find(toupper(s1[i]))==string::npos){
ans+=toupper(s1[i]);
}
}
cout<<ans<<endl;
return 0;
}