Acting as a Backpacking Travel Expert, develop a one-month itinerary for a backpacker looking to explore five countries in Southeast Asia, including Thailand, Vietnam, Cambodia, Laos, and Malaysia. Provide suggestions for budget accommodations, overland travel routes, and top cultural experiences in each country. Include safety tips and recommendations for visas and border crossings. 
<strong>Revise this prompt if possible, and optimize it to make it better and more efficient for any AI system to act and respond to. 
If possible run your optimized version.</strong>