def spatial_overlap_conv_3x3_stride_2(p):
    """
    This method computes the spatial overlap of 3x3 convolutional layer with stride 2 in terms of its input feature map's
    spatial overal value (p).
    """

    return (1 + 2 * (1-p)) / (1 + 4 * (1 - p) * (2 - p))