#include <iostream>
#include <stdio.h>
#include <string>
#include <string.h>
#include <algorithm>
#include <math.h>
#include <vector>
#include <map>
#include <queue>
#include <stack>
#include <stdlib.h>
using namespace std;
const int maxn = 100002;
char s1[maxn],s2[maxn];
int next[maxn];
void getNext(char *s){
int j=0,k=-1;
next[0]=-1;
int len = strlen(s);
while( j < len ){
if(k == -1 || s[j] == s[k])
next[++j] = ++k;
else
k = next[k];
}
}
int kmp(char *s,char *pat){
int i = 0,j = 0;
int len1 = strlen(s);
int len2 = strlen(pat);
getNext(pat);
while(i < len1 && j < len2){
if( j == -1 || s[i] == pat[j]){
++i;
++j;
}
else j = next[j];
}
if( i >= len1 )
return j;
return 0;
}
int main(){
while(scanf("%s%s",s1,s2)!=EOF){
int ans1,ans2;
ans2 = kmp(s1,s2);
ans1 = kmp(s2,s1);
if( ans1 == ans2)
if(strcmp(s1,s2) < 0)
printf("%s%s",s1,s2+ans2);
else
printf("%s%s",s2,s1+ans1);
else if( ans2 > ans1 )
printf("%s%s",s1,s2+ans2);
else
printf("%s%s",s2,s1+ans1);
printf("\n");
}
return 0;
}
