Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: Japan has been a late adopter when it comes to smartphones, but it's catching up quickly - already more than half the population owns one. But Tokyo is a crowded city, and warnings are being issued about the risk of mass collisions among phone-using pedestrians at one busy crossing.

Japan enters the era of smartphones and 'dumbwalking'