Utility Topic

Imagine one day you are walking through a public park and you see an overweight rich kid eating an enormous tub of ice cream.  Nearby are three somewhat younger children from the local orphanage, looking on in envy of a treat they have never had.  There is one happy person and three unhappy ones. This seems like a situation where utilitarianism should be applied.  What options are there for making the world a happier place?  Which one would maximize overall happiness, and why?