def METHOD_NAME(x, m):
    '''
    :param x: a list of 2D-points, off diagonal, x_0... x_{k-1}
    :param m: total amount of points taken into account, that is we have (m-k) copies of diagonal
    :returns: the weighted mean of x with (m-k) copies of the diagonal
    '''
    k = len(x)
    if k > 0:
        w = np.mean(x, axis=0)
        w_delta = (w[0] + w[1]) / 2 * np.ones(2)
        return (k * w + (m-k) * w_delta) / m
    else:
        return np.array([0, 0])