The circumference of a circle is 1.26 meters. Two ants start from both ends of the diameter at the same time and crawl towards each other along the circumference. These two ants crawl 5.5 cm and 3.5 cm per second respectively. Every time they crawl for 1 second, 3 seconds, 5 seconds... (continuous odd numbers), they turn around and crawl. Then, when they meet, how many seconds have they been crawling.
一个圆的周长为1.26米，两只蚂蚁从一条直径的两端同时出发沿圆周相向爬行．这两只蚂蚁每秒分别爬行5.5厘米和3.5厘米．它们每爬行1秒，3秒，5秒…(连续的奇数)，就调头爬行．那么，它们相遇时，已爬行的时间是多少秒．
<gadget id="calculator">1 - 3</gadget>
<output>-2</output>

<gadget id="calculator">1.26 / 2</gadget>
<output>0.63</output>

<gadget id="calculator">3.5 + 5.5</gadget>
<output>9</output>

<gadget id="calculator">100 / 9</gadget>
<output>100/9 = around 11.111111</output>

<gadget id="calculator">0.63 * (100/9)</gadget>
<output>7</output>

<gadget id="calculator">5 - 7</gadget>
<output>-2</output>

<gadget id="calculator">9 - 11</gadget>
<output>-2</output>

<gadget id="calculator">13 + 11 + 9 + (-2) + (-2) + (-2) + 13 + 5 + 3 + 1</gadget>
<output>49</output>

<result>49</result>