Suppose file corp$\_($p$)$hones has the records shown below:

$219$:$432$:$4567$: Harrison:Joel:M:$4540$:Accountant:$09-12-1985$

$219$:$432$:$4587$: Mitchell:Barbara:C:$4541$:Admin Asst:$12-14-1995$

$219$:$432$:$4589$: Olson:Timothy:H:$4544$:Supervisor:$06-30-1983$

$219$:$432$:$4591$:Moore:Sarah:H:$4500$:Dept Manager:$08-01-1978$

$219$:$432$:$4527$: Polk:John:S:$4520$:Accountant:$09-22-1998$

What command would you use to extract just the last names in it$?$