Five-decades-long OR Five-long-decades?

Hi, EKW, and welcome to the G.E,

@EKW posted:

I came across this sentence:

In January 2013, President Raul Castro ended a five-decades-long policy on limiting international travel for Cuban citizens.

Is that sentence grammatically correct?

No, it isn't. It should be 'decade' in the singular form, (not decades). It is a compound adjective here. David and Gustavo have asserted this point already. See here:

https://thegrammarexchange.inf...1#595653434403800051

Thank you.