A couple with three children waited in line at San Francisco's Pier 41 to
purchase tickets for a boat trip to Alcatraz.  Others watched with varying
degrees of sympathy and irritation as the young children fidgeted, whined,
and punched one another. 
 
The frazzled parents reprimanded them to no avail. 
 
Finally, they reached the ticket window. 
 
"Five tickets, please," the father said.  "Two round trip, three one way."