oh but if you are doing 2 5 month stints you gotta go 2 month visa, 30 day extension, border run, 30 day extension. Don't do 2 border runs in the first 5 months if both by land as you are only permitted 2 of them in a calendar year. So if you want 10 months total, you'll have to do it this way unless you're flying out and back on a border run. Important you know this