X1 type for year, plan to travel to other Asian countries what do I put as "longest stay"

I'm applying for XI type. While I'm out in China I want to travel to Japan/Korea etc but I don't know how many times I'll be leaving China, or how long each trip out will be..... how do I represent this on the application form where it says "longest intended stay in China among all entries?" Should I just give an estimate that's over 180 (because my visa is for long term study over 180 days).

Thanks.