Class 1 of the fourth grade uses the class fee to purchase three kinds of stationery A, B, and C with unit prices of 3 yuan, 2 yuan, and 1 yuan respectively. It is known that the number of purchased type B stationery is 2 less than the number of purchased type A stationery, and the cost of purchasing type A stationery does not exceed half of the total cost. If the purchased three kinds of stationery share exactly 66 yuan, then how many pieces of B stationery can be purchased at most?
四年级一班用班费购买单价分别为3元、2元、1元的甲、乙、丙三种文具．已知购买乙种文具的件数比购买甲种文具的件数少2件，且购买甲种文具的费用不超过总费用的一半．若购买的三种文具恰好共用了66元，那么乙种文具最多购买了多少件．
<gadget id="calculator">11 - 2</gadget>
<output>9</output>

<result>9</result>