import sys

sys.setrecursionlimit(10 ** 7)
input = sys.stdin.readline
f_inf = float('inf')
mod = 10 ** 9 + 7


def CRT(B, M):
    def extgcd(a, b):
        if b:
            d, y, x = extgcd(b, a % b)
            y -= (a // b) * x
            return d, x, y
        return a, 1, 0

    b1, m1 = 0, 1
    for b2, m2 in zip(B, M):
        d, p, q = extgcd(m1, m2)
        if (b2 - b1) % d != 0:
            return 0, -1
        tmp = (b2 - b1) // d * p % (m2 // d)
        b1 += m1 * tmp
        m1 *= m2 // d
    return b1 % m1, m1


def resolve():
    X, Y = [], []
    for _ in range(3):
        x, y = map(int, input().split())
        X.append(x)
        Y.append(y)

    res = CRT(X, Y)
    print(res[0] if res[0] else res[1])


if __name__ == '__main__':
    resolve()