set serveroutput on

declare

v_start employees.employee_id%type;

v_end employees.employee_id%type;

v_count number(1);

select min(employee_id) + 1 , max(employee_id) - 1 into v_start, v_end

from employees;

for empid in v_start..v_end

loop

select count(*) into v_count

from employees

where employee_id = empid;

if v_count = 0 then

dbms_output.put_line(empid);

end if;

end loop;

end;