凡是 … 都 (all / any without exception)

"Any / all without exception"

• each and every凡是fán shì + Noun + all / both都dōu / then / just就jiù / same一律yī lǜ + Predicate = "all / any (such) …".
• each and every凡是fán shìstudent学生xué shēngall / both都dōucan / may可以kě yǐto participate参加cān jiā = "any student may take part."
• each and every凡是fán shì sweeps in every member of a category.

each and every凡是fán shì + Noun + all / both都dōu …

• each and every凡是fán shì marks a whole class; all / both都dōu echoes "all of them".

all凡是fán shìstudents学生xué shengall都dōumay可以kě yǐtake part参加cān jiā。

• each and every凡是fán shìstudent学生xué shēngall / both都dōucan / may可以kě yǐto participate参加cān jiā = "any student may take part."

Recap

Read the full reference: HSK 6 grammar — Adverbs.