#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;

const int N = 2e5+10;
int Next[N];
char S[N], T[N];
char a[N],b[N];
char tmp[N];
char res1[N],res2[N];
int slen, tlen;//注意每次一定要计算长度
int alen,blen;
int ans;
int len1,len2;
void getNext()
{
    int j, k;
    j = 0; k = -1; Next[0] = -1;
    while(j < tlen)
        if(k == -1 || T[j] == T[k])
            Next[++j] = ++k;
        else
            k = Next[k];

}
int main()
{
    while(scanf("%s%s",a,b)!=EOF){
     alen=strlen(a);
     blen=strlen(b);
     for(int i=0;i<blen;i++)
        T[i]=b[i];
      T[blen]=‘#‘;
     for(int i=0;i<alen;i++)
     T[blen+1+i]=a[i];
     tlen=alen+blen+1;
     T[tlen]=0;
     getNext();
     ans=Next[tlen];
     for(int i=0;i<alen;i++)
     res1[i]=a[i];
     for(int i=ans;i<blen;i++)
     res1[alen+i-ans]=b[i];
     len1=alen+blen-ans;
     res1[len1]=0;
     memcpy(tmp,a,sizeof(a));
     memcpy(a,b,sizeof(b));
     memcpy(b,tmp,sizeof(tmp));
     swap(alen,blen);

      for(int i=0;i<blen;i++)
        T[i]=b[i];
      T[blen]=‘#‘;
     for(int i=0;i<alen;i++)
     T[blen+1+i]=a[i];
     tlen=alen+blen+1;
     T[tlen]=0;
     getNext();
     ans=Next[tlen];
     for(int i=0;i<alen;i++)
     res2[i]=a[i];
     for(int i=ans;i<blen;i++)
     res2[alen+i-ans]=b[i];
     len2=alen+blen-ans;
     res2[len2]=0;
        if(len1<len2)
        printf("%s\n",res1);
        else if(len1>len2)
        printf("%s\n",res2);
        else
        {
            if(strcmp(res1,res2)<=0)
            printf("%s\n",res1);
            else
            printf("%s\n",res2);
        }
    }
    return 0;
}