def get_stride(resnet_unit_id, block_id):
    """
    Determines the convolution stride.

    :param int resnet_unit_id: Which resnet unit
    (e.g. 0 is conv2_x, 1 is conv3_x)
    :param int block_id: Which block in the resnet unit (i.e. in the third
    unit of a 152-layer resnet, block_id=36)
    :return: Stride
    """
    if resnet_unit_id == 0 or block_id != 0:
        return 1
    else:
        return 2