def Muller(mev, dis):
    x2 = []
    while 1:
        x = random.uniform(-1, 1)
        y = random.uniform(-1, 1)
        s = x**2 + y**2
        if 0 < s and s <= 1:
            z0 = x * math.sqrt(-2 * math.log(s) / s)
            z1 = y * math.sqrt(-2 * math.log(s) / s)
            x2.append(mev + dis * z0)
            x2.append(mev + dis * z1)
            if len(x2) == 20:
                return x2

print Muller(mev, dis)