The United Pingdom (UP) is a mysterious country that exists on the Internet only. In the UP, the
two subdomains kate.royal.gov.up and william.royal.gov.up shall be united to couple.royal.gov.up.
However, according to the strict rules of the domain administration center UPNIC, two subdomains
may get “married” only if their popularity values are not too different. The popularity value of a
subdomain is an integer number.

Given the popularity values of two subdomains, compute their popularity difference, which is the
absolute difference between the popularity values.