#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int fh = 1, x = 0;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') fh = -1;
    ch = getchar();
  }
  while ('0' <= ch && ch <= '9') {
    x = (x << 3) + (x << 1) + ch - '0';
    ch = getchar();
  }
  return fh * x;
}
inline void write(const int x) {
  if (x > 9) write(x / 10);
  putchar(x % 10 + '0');
}
inline int _abs(const int x) { return x >= 0 ? x : -x; }
inline int _max(const int x, const int y) { return x >= y ? x : y; }
inline int _min(const int x, const int y) { return x <= y ? x : y; }
inline int _gcd(const int x, const int y) { return y ? _gcd(y, x % y) : x; }
inline int _lcm(const int x, const int y) { return x * y / _gcd(x, y); }
char a[100005], b[100005], ans[100005];
int lena, lenb;
signed main() {
  scanf("%s %s", a, b);
  ans[0] = a[0];
  int i;
  for (i = 1; i < strlen(a); i++)
    if (a[i] < b[0])
      ans[i] = a[i];
    else
      break;
  ans[i] = b[0];
  printf("%s\n", ans);
  return 0;
}
