DECLARE
n NUMBER;
v_empid NUMBER;
v_name VARCHAR2 (20);
v_dept NUMBER;
v_sal NUMBER;
BEGIN
n := '&num';

SELECT ROWNUM AS RANK, employee_id, first_name, last_name, department_id, salary
INTO v_empid, v_name, v_dept, v_sal
FROM (SELECT employee_id, first_name, last_name, department_id, salary
FROM employees
WHERE salary != '0'
ORDER BY salary DESC)
WHERE ROWNUM <= n;

FOR i IN 1 .. n
LOOP
DBMS_OUTPUT.put_line (v_sal || '');
END LOOP;
END;