A class of students bought 120 bottles of soda, and 4 empty bottles can be exchanged for 1 bottle of soda. How many bottles of soda can they drink at most?
某班同学买了120瓶汽水，4个空瓶可以换一瓶汽水，他们最多能喝到多少瓶汽水．
<gadget id="calculator">120 + 30 + 7 + 2 + 1</gadget>
<output>160</output>

<result>160</result>