import sys
input = sys.stdin.readline
from math import gcd

def lcm(x, y):
    return x*y//gcd(x, y)

def ext_gcd(a, b):
    if b==0:
        return 1, 0
    
    s, t = ext_gcd(b, a%b)
    return t, s-a//b*t

def crt(rs, ms):
    r, m = 0, 1
    
    for ri, mi in zip(rs, ms):
        p, q = ext_gcd(m, mi)
        g = gcd(m, mi)
        
        if (ri-r)%g!=0:
            return -1
        
        r += m*(ri-r)//g*p
        m *= mi//g
        r %= m
    
    return r

rs, ms = [], []

for _ in range(3):
    r, m = map(int, input().split())
    rs.append(r)
    ms.append(m)

ans = crt(rs, ms)

if ans==0:
    print(lcm(lcm(ms[0], ms[1]), ms[2]))
else:
    print(ans)