how do i show the last 4 users which entered the system(not last 4 logins)
i tried this
last -4|cut -d" " -f1| uniq -u

but its not working

i was told to
"Do the last command ... send (all) the output to cut and get just the user, send THAT output on to uniq (to get unique values) then send that on to head to get the top 4 entries."

can some one help me to interpret these words to command?? :

about the first part ,do i need only wright "last"
about the second part ,what option to use in the uniq command

and the last one
how do i send that on to head to get the top 4 entries??

i dont know if this is the right way.
i dont care what command will lead to the result


i just want the list of the last 4 users which logged in??

i tried lots of combination that didnt work
plz help