Austrian Zebra and Xiaomei are traveling in the same direction in cities A and B, which are 111 kilometers apart. It is known that Xiaomei travels first for 3 hours, Austrian zebra travels 35 kilometers per hour, and Xiaomei travels 23 kilometers per hour. So, how many hours after Ao Zebra set off to catch up with Xiaomei?
奥斑马和小美分别在相距111千米的A、B两城，同向而行．已知小美先行3小时，奥斑马每小时行35千米，小美每小时行23千米．那么，奥斑马出发后多少小时追上小美？
<gadget id="calculator">23 * 3</gadget>
<output>69</output>

<gadget id="calculator">111 + 69</gadget>
<output>180</output>

<gadget id="calculator">35 - 23</gadget>
<output>12</output>

<gadget id="calculator">180 / 12</gadget>
<output>15</output>

<result>15</result>