def crt(a1,m1,a2,m2):
    x,y,g=egcd(m1,m2)
    if (a2-a1)%g:
        return (-1,0)
    lcm=m1//g*m2
    return ((a1+(a2-a1)//g*m1*x)%lcm,lcm)


def egcd(x,y):
    a1,b1=1,0
    a2,b2=0,1
    while x%y:
        q,w=x//y,x%y
        a3,b3=a1-a2*q,b1-b2*q
        x,y=y,w
        a1,b1=a2,b2
        a2,b2=a3,b3
    return a2,b2,y


q,w=0,1
for i in range(3):
    a,b=map(int,input().split())
    q,w=crt(q,w,a,b)
print(q)