#pragma GCC optimize(2)
#include<bits/stdc++.h>
using namespace std;
#define int long long
string s1, s2, s3;
signed main()
{
cin>>s1>>s2;
s3 = "zzzzzzzzzzzzzzzzzzzz";
for(int len1 = 1; len1<=s1.size();++len1)
{
for(int len2 = 1;len2<=s2.size();++len2)
{
string t1 = s1.substr(0, len1), t2 = s2.substr(0, len2);
s3 = min(s3, t1+t2);
}
}
cout<<s3<<endl;
return 0;
}