def calc_relu(func, in_data, **kwargs):
    """[ReLU](https://docs.chainer.org/en/v4.3.0/reference/generated/chainer.functions.relu.html)

    Max operation can be executed by a single instruction.
    chainer-computational-cost considers it as one floating point operation.

    | Item   | Value |
    |:-------|:------|
    | FLOPs  | $$\| x \|$$ |
    | mread  | $$\| x \|$$ |
    | mwrite | $$\| x \|$$ |
    | params | N/A |
    """
    x, = in_data
    return (x.size, x.size, x.size, {})