#include <iostream>
#include <string.h>
using namespace std;
int main(){
int loadA[26];
int loadB[26];
char listA[1000];
char listB[1000];
for(int clr=0;clr<26;clr++){
loadA[clr]=0;
loadB[clr]=0;
}
while(cin>>listA){
cin>>listB;
int tem;
int len=strlen(listA);
for(int i=0;i<len;i++){
tem=(int)listA[i]-97;
loadA[tem]=loadA[tem]+1;
}
len=strlen(listB);
for(int i=0;i<len;i++){
tem=(int)listB[i]-97;
loadB[tem]=loadB[tem]+1;
}
char show;
for(int i=0;i<26;i++){
if(loadA[i]>0 && loadB[i]>0){
if(loadA[i]>loadB[i]){
for(int j=0;j<loadB[i];j++){
show=(char)i+97;
cout << show ;
}
}
else{
for(int j=0;j<loadA[i];j++){
show=(char)i+97;
cout << show;
}
}
}
if(i==25){
cout << endl;
}
}
for(int cle=0;cle<26;cle++){
loadA[cle]=0;
loadB[cle]=0;
}
}
}
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