import random

P, Q, x , y = map(int, input().split())

def reverse(x):
    return int(str(x)[::-1])

while True:
    k = random.randint(0, 10 ** 100)
    rev_N = k * Q + y
    if rev_N % 10 == 0:
        continue
    N = reverse(rev_N)
    if N % P == x:
        print(N)
        break