A compound of the formulawherein R1, R2 and R3 are as defined above, useful as inhibitors of protein kinases, such as the enzyme Janus Kinase 3. The liquid crystal display panel has a first substrate, a second substrate, and a liquid crystal layer provided between the first substrate and the second substrate. One USB port is capable of receiving electrical power supplied from a USB port of a connected electric appliance such as a personal computer for driving built-in fans of the present invention. Each usage right may specify a digital ticket which must be present before the right may be exercised.