import sys
import math
from functools import reduce

def lcm_base(x, y):
    return (x * y) // math.gcd(x, y)

def lcm(*numbers):
    return reduce(lcm_base, numbers, 1)

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


x1, y1 = map(int, input().split())
x2, y2 = map(int, input().split())
x3, y3 = map(int, input().split())

# hoge = x (mod y), i = 1,2,3 をみたす最小のhogeを求める。

# print(x1, y1)
# print(x2, y2)
# print(x3, y3)

ymin = lcm(*[y1, y2, y3])

# print(ymin)

for j in range(ymin):
    # print(j)
    if j % y1 == x1 and j % y2 == x2 and j % y3 == x3:
        print(j)
        sys.exit()

print(-1)