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 a == 0:
            return b, 0, 1
        g, y, x = extGcd(b % a, a)
        return g, x - (b // a) * y, y
    b1 = 0
    m1 = 1
    for i in range(len(B)):
        b2 = B[i]
        m2 = M[i]
        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()