#include <bits/stdc++.h>
using namespace std;
inline char gc() {
  static char buf[1 << 14], *p1 = buf, *p2 = buf;
  return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 14, stdin), p1 == p2)
             ? EOF
             : *p1++;
}
template <class T>
inline int read(T& x) {
  x = 0;
  bool f = 1;
  char c = getchar();
  for (; !isdigit(c); c = getchar()) {
    if (c == '-') f ^= 1;
    if (c == -1) return -1;
  }
  for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
  x = f ? x : -x;
  return 1;
}
template <class T>
inline void wr(T x) {
  if (x < 0) putchar('-'), x = -x;
  if (x > 9) wr(x / 10);
  putchar(x % 10 | 48);
}
const int N = 5e5 + 10;
char s1[N], s2[N];
int n, m, net[N], num1, num0;
inline void getnet() {
  for (int i = 2, j = 0; i <= m; i++) {
    for (; j && s2[j + 1] != s2[i];) j = net[j];
    if (s2[j + 1] == s2[i]) {
      net[i] = ++j;
    } else {
      net[i] = 0;
    }
  }
}
int main() {
  scanf("%s%s", s1 + 1, s2 + 1);
  n = strlen(s1 + 1);
  m = strlen(s2 + 1);
  getnet();
  for (int i = 1; i <= n; ++i)
    if (s1[i] == '1')
      ++num1;
    else
      ++num0;
  for (int i = 1, k = 0; i <= n; ++i) {
    if (s2[k + 1] == '0')
      --num0;
    else
      --num1;
    if (num0 < 0 || num1 < 0) {
      if (s2[k + 1] == '0')
        ++num0;
      else
        ++num1;
      break;
    }
    putchar(s2[k + 1]);
    ++k;
    if (k == m) k = net[k];
  }
  for (int i = 1; i <= num0; ++i) putchar('0');
  for (int i = 1; i <= num1; ++i) putchar('1');
  return 0;
}
