def extgcd(a, b):
    """
    拡張Euclidの互除法
    INPUT:
        a, b
    OUTPUT:
        d: gcd(a, b)
        (x, y): ax + by = d の解
    """
    if b == 0:
        return a, 1, 0
    d, y, x = extgcd(b, a % b)
    y -= a // b * x
    return d, x, y


def crt(B, M):
    """
    中国剰余定理
    x ≡ b0 (mod M0)
    x ≡ b1 (mod M1)
    x ≡ b2 (mod M2)
    となるxを求める
    INPUT:
        B:[b0,b1,..]
        M:[m0,m1,..]
    OUTPUT:
        (x, mod) -> x:最小の答え(0<=x<mod)
                    mod:lcm(m0,m1,..)
        (0,-1) -> 解がない場合
    """
    x = 0
    mod = 1
    for b, m in zip(B, M):
        d, p, _ = extgcd(mod, m)
        if (b - x) % d != 0:
            return 0, -1
        x += (b - x) // d * p % (m // d) * mod
        mod *= m // d
    return x % mod, mod


if __name__ == "__main__":
    bm = tuple(tuple(map(int, input().split())) for _ in range(3))
    b, m = zip(*bm)
    x, mod = crt(b, m)
    if mod == -1:
        print(-1)
        exit()
    if x == 0:
        x = mod
    print(x)