import sys


def count_bits(s):
    return [s.count("0"), s.count("1")]


# 1 - in case where a >= b
# 0 - otherwise
def compare_bits_count(a, b):
    if a[0] >= b[0] and a[1] >= b[1]:
        return 1
    else:
        return 0


def subtract_bits_count(a, b):
    return [a[0] - b[0], a[1] - b[1]]


def z_function(s):
    n = len(s)
    l = 0
    r = 0
    z = [0 for x in range(n)]
    for i in range(1, n):
        z[i] = max(0, min(r - i, z[i - l]))
        while i + z[i] < n and s[z[i]] == s[i + z[i]]:
            z[i] += 1
        if i + z[i] > r:
            l = i
            r = i + z[i]
    return z


s = input()
t = input()

s_bits_count = count_bits(s)
t_bits_count = count_bits(t)

if compare_bits_count(s_bits_count, t_bits_count) == 0:
    print(s)
    sys.exit()

result = t
s_bits_count = subtract_bits_count(s_bits_count, t_bits_count)

r = ""

z = z_function(t)
for i in range(len(t) // 2, len(t)):
    if z[i] == len(t) - i:
        r = t[len(t) - i:]
        r_bits_count = count_bits(r)
        break

if len(r) == 0:
    r = t
    r_bits_count = t_bits_count

while s_bits_count[0] > 0 or s_bits_count[1] > 0:
    if compare_bits_count(s_bits_count, r_bits_count) == 1:
        result += r
        s_bits_count = subtract_bits_count(s_bits_count, r_bits_count)
    else:
        result += '0' * s_bits_count[0]
        result += '1' * s_bits_count[1]
        break

print(result)