> For the complete documentation index, see [llms.txt](https://www.pythonclassroom.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.pythonclassroom.com/python-curriculum-map/pedagogy/activities/crossing-the-bridge.md). # Crossing the Bridge Alice, Bob, Carrie, and Dan have to cross a rickety bridge. The bridge can only hold two people at a time. They also have a flashlight, and one person on the bridge must be always holding the flashlight. Alice can cross the bridge in 1 minute, Bob can cross the bridge in 2 minutes, Carrie can cross the bridge in 5 minutes, and Dan can cross the bridge in 10 minutes. What is the fastest amount of time that all four of them can cross the bridge? * This problem has no tricks, no one is carrying another person, dragging them, running, etc. * There is a good answer and a best answer * You are as fast as the slowest person on the bridge --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://www.pythonclassroom.com/python-curriculum-map/pedagogy/activities/crossing-the-bridge.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.