def extgcd(a, b):
    if b == 0:
        return 1, 0, a
    q, r = divmod(a, b)
    x, y, d = extgcd(b, r)
    s, t = y, x-q*y
    return s, t, d

def mod(a, m):
    return (a%m + m)%m;

def CRT_list(b, m):
    #b: list
    #m: lsit
    r, M = 0, 1
    for i in range(len(b)):
        p, q, d = extgcd(M, m[i])
        if (b[i]-r)%d != 0:
            return 0, -1
        temp = (b[i]-r)//d * p % (m[i]//d)
        r += M * temp
        M *= m[i]//d
    return mod(r, M), M

import math
from functools import reduce
def lcm_base(x, y):
  return (x * y) // math.gcd(x, y)

def lcm_list(numbers):
  return reduce(lcm_base, numbers, 1)

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

if X[0] == 0 and X[1] == 0 and X[2] == 0:
    print(lcm_list(Y))
    exit()

r, M = CRT_list(X, Y)
if M == -1:
    print(-1)
else:
    print(r)