def gcd(a, b):
    if b == 0:
        return a
    else:
        return gcd(b, a%b)

def extgcd(a, b):
    #拡張ユークリッド互除法
    #ax + by = gcd(a, b)となる(x, y)を求めます
    if b == 0:
        return [1, 0]

    q = a//b
    r = a%b
    
    s, t = extgcd(b, r)
    y = s - q*t
    return [t, y]

def CRT(rs, ms):
    R = 0
    M = 1
    for r, m in zip(rs, ms):
        g = gcd(M, m)
        
        # assert r%g == R%g
        if r%g != R%g:
            return [-1, -1]
        s, _ = extgcd(M, m)

        lcm = m*M // g
        R += (r - R)//g * M * s
        R %= lcm
        M = lcm
    return [R, M]

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

print(CRT(x, y)[0])