A tour group has reserved some houses for a group of tourists in Xinxin Hotel. If all the tourists are arranged to live in a room with 2 people, 7 people have no place to live; if 8 people are arranged to live in a room with 2 people, the rest of the tourists live in a room with 3 people. , then just stay. How many people are there in this group of tourists?
某旅行团为一批游客在新新宾馆预定了一些住房，如果将游客都安排住2人一间，7人没处住；如果安排8人住2人一间，其余游客住3人一间，则正好住下．这批游客共多少人．
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">3 - 7</gadget>
<output>-4</output>

<gadget id="calculator">16 + (-4)</gadget>
<output>12</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<gadget id="calculator">12 + 7</gadget>
<output>19</output>

<result>19</result>