i want to execute this procedure in sql plus usnig exec statement

iam trying like this

declare
begin
exec pkg.procedurea
end;
but my question is what to pass the value of in out parameter in executing the procedure.

i have created the ref cursor type in package as below

CURSOR c1 IS
SELECT UD_USER_ID,
UD_USER_Name
FROM tablea
WHERE end_flag <> 'Y';

TYPE rc_cursor IS REF CURSOR RETURN c1%ROWTYPE;


name of the procedure to execute is below.

PROCEDURE procedureA
( pc_ref IN OUT pkg_ABC.rc_cursor)
AS
BEGIN
OPEN pc_ref
FOR SELECT UD_USER_ID,
UD_USER_Name
FROM tablea
WHERE end_flag <> 'Y';


END procedureA;

please help in this regard.
thanks in advance.