Pirates On Parade

Davy Jones wants his men to line up on parade. The men are to line up in pairs, from shortest to tallest. However, two pirates in the same pair can only differ in height by at most 2 inches. You start lining up the pirates in pairs in order, starting with the shortest pirate. If after selecting a pirate it is not possible to find a pirate sufficiently near his height (or if there are no pirates left), the unpaired pirate will be forced to walk the plank! You may assume no pirates are exactly the same height.

The input will be a list of pirates listed by name and their height in inches as an integer.

The output should be the names of pairs of pirates, each on a single line, in order from shortest to tallest. The shorter pirate in each pair should be first. Any pirates forced to walk the plank should not be listed.