It is known that 4 bottles of mineral water can be exchanged for one bottle of mineral water. There are 16 empty bottles of mineral water. If you don’t spend money, how many bottles of mineral water can you drink at most?
已知4个矿泉水瓶子可以换矿泉水一瓶，现有16个矿泉水空瓶，若不花钱，最多可以喝多少瓶矿泉水．
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<result>5</result>