A construction project has been tasked with building a four-lane road from a remote mountain fortress to a major expressway lying at the base of the mountain. The slope leading to the mountain fortress is so precipitous that the only conceivable way to carry out the project is by building the road downhill, since construction equipment is able to move down, but not up, the steep terrain. The foreman has devised the following solution: dismantle each construction vehicle and tie a part upon the back of a donkey, an animal capable of making the steep ascent. The foreman has at his disposal more than 100 donkeys, each of which is capable of making multiple trips up the mountain.
In order for the foreman's plan to be successful, which of the following pieces of information is most important?