## https://yukicoder.me/problems/no/1819


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

    while True:
        if y % 10 == 0:
            y += Q

        N = int(str(y)[::-1])
        n_array = [str(N)]
        init_n = N % P
        n_array2 = n_array.copy()
        n = init_n
        if init_n != x:
            n *= 10
            n %= P
            n_array2.append("0")
            while n != x and init_n != n:
                n *= 10
                n %= P
                n_array2.append("0")
            
            if n == x:
                print("".join(n_array2))
                return
        else:
            print("".join(n_array2))
            return

        y += Q

if __name__ == "__main__":
    main()