Lele, Huanhuan, and Tiantian each have some stickers. Lele gave 13 stickers to Huanhuan, and 15 stickers from Huanhuan to Tiantian. After that, the three of them had the same number of stickers. How many more stickers did Huanhuan have than Tiantian?
乐乐、欢欢、甜甜各有一些贴画，乐乐给欢欢13张，欢欢给甜甜15张后，三个人的贴画张数就一样多，原来欢欢比甜甜多几张？
<gadget id="calculator">15 - 13</gadget>
<output>2</output>

<gadget id="calculator">15 + 2</gadget>
<output>17</output>

<result>17</result>