# coding=utf-8

import sys

def egcd(x, y):
	if y == 0:
		return (x, 1, 0)
	(d, a, b) = egcd(y, x % y)
	return (d, b, a - (x // y) * b)

def crt(p, m, q, n):
	a, d, r = egcd(p, q)
	if (n - m) % a != 0:
		return (-1, -1)
	mod = p * (q // a)
	a = (d * ((n - m) // a) * p + m) % mod
	return (a, mod)

def chinese_remainder(items):
	xx = 0
	yy = 1
	for x, y in items:
		xx, yy = crt(y, x, yy, xx)
		if xx == -1:
			print(-1)
			sys.exit(0)
	if xx == 0: xx = yy
	return xx

n = 3
x = [0] * n
for i in range(n):
	x[i] = tuple(map(int, input().split()))
print(chinese_remainder(x))