首要

the most important / of chief importance

head / chief / first (occasion, thing etc) / classifier for poems, songs etc

to demand / to request / to coerce

important / vital / to want / to ask for / will / going to (as future auxiliary) / may / must / (used in a comparison) must be / probably / if

(bound form) to demand; to coerce

to want; to need; to ask for / will; shall; about to / need to; should / if (same as 要是[yao4 shi5]) / (bound form) important