def METHOD_NAME(self, prediction):
    pos = paddle.slice(
        prediction, axes=[0, 1], starts=[0, 0], ends=[64, 1])
    neg = paddle.slice(
        prediction, axes=[0, 1], starts=[64, 0], ends=[128, 1])
    loss_part1 = paddle.subtract(
        paddle.full(
            shape=[64, 1], fill_value=1.0, dtype='float32'), pos)
    loss_part2 = paddle.add(loss_part1, neg)
    loss_part3 = paddle.maximum(
        paddle.full(
            shape=[64, 1], fill_value=0.0, dtype='float32'),
        loss_part2)
    avg_cost = paddle.mean(loss_part3)
    return avg_cost