In this task, you will be presented with a question and you have to answer the question based on your knowledge. Your answers should be as short as possible.

Example input: Who were the builders of the mosque in Herat with fire temples ?
Example output: Ghurids
Example explanation: This is a good example. Ghurids were the builders of the mosque in Herat with fire temples.
Q: What is the difference between the number of days of competion for the ones that are part of an American tour and the one that are part of a European tour ?
A:
7