P, Q, x, y = map(int, input().split())
for n in range(10 ** 4):
    q = n * Q + Q
    z = n * Q + y
    d = len(str(q))
    rev_z = int(str(z).zfill(d)[::-1])
    rev_q = int(str(q)[::-1])
    if (x - rev_q) % P == 0 or rev_z % P == 0:
        continue
    goal = (x - rev_q) * pow(rev_z, P - 2, P) % P
    k = d
    t = pow(10, k, P)
    # print(goal)
    while t != goal:
        k += 1
        t *= 10
        t %= P
    # print(pow(10, k, P), goal) 
    break

answer_int = rev_z * 10 ** k + rev_q
# print(k)
# print(q, z)

# assert len(str(answer_int)) <= 10 ** 5
# assert answer_int % P == x, f"{answer_int % P, x}"
# assert int(str(answer_int)[::-1]) % Q == y, f"{answer_int % Q, y}"

print(answer_int)