A store stipulates that 3 empty soda bottles can be exchanged for one bottle of soda. Xiaohua buys 10 bottles of soda and uses the empty soda bottles to exchange for soda after drinking. How many bottles of soda can Xiaohua drink in total?
某商店规定3个空汽水瓶可以换一瓶汽水，小华买了10瓶汽水，喝完后用空汽水瓶去换汽水，小华一共可以喝到多少瓶瓶汽水．
<gadget id="calculator">10 + 3 + 1 + 1</gadget>
<output>15</output>

<result>15</result>