#include <bits/stdc++.h>
using namespace std;
int main() {
  string s, p;
  cin >> s >> p;
  int len = s.size();
  cout << s[0];
  for (int i = 1; i < len; i++) {
    if (s[i] < p[0])
      cout << s[i];
    else
      break;
  }
  cout << p[0] << endl;
  return 0;
}
