The circumference of a circle is 5.4 meters. Two ants start from both ends of a diameter and crawl towards each other along the circumference. The two ants crawl 5.5 cm and 3.5 cm per second respectively. They turn around and crawl every time they crawl for 1 second, 3 seconds, 5 seconds... (continuous odd number). How long had the two ants been crawling when they first met?
一个圆的周长是5.4米，两只蚂蚁从一条直径的两端同时出发沿圆周相向爬行，这两只蚂蚁每秒钟分别爬行5.5厘米和3.5厘米．它们每次爬行1秒、3秒、5秒…(连续奇数)就调头爬行．两只蚂蚁第一次相遇时，已爬行了多长时间？
<gadget id="calculator">1 - 3</gadget>
<output>-2</output>

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

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

<gadget id="calculator">13 - 15</gadget>
<output>-2</output>

<gadget id="calculator">17 - 19</gadget>
<output>-2</output>

<gadget id="calculator">21 - 23</gadget>
<output>-2</output>

<gadget id="calculator">35 - 27</gadget>
<output>8</output>

<gadget id="calculator">29 - 31</gadget>
<output>-2</output>

<gadget id="calculator">33 - 35</gadget>
<output>-2</output>

<gadget id="calculator">37 - 39</gadget>
<output>-2</output>

<gadget id="calculator">41 - 43</gadget>
<output>-2</output>

<gadget id="calculator">45 - 47</gadget>
<output>-2</output>

<gadget id="calculator">49 - 51</gadget>
<output>-2</output>

<gadget id="calculator">53 - 55</gadget>
<output>-2</output>

<gadget id="calculator">(-2) + (-2) + (-2) + (-2) + (-2) + (-2) + 8 + (-2) + (-2) + (-2) + (-2) + (-2) + (-2) + (-2) + 57</gadget>
<output>39</output>

<gadget id="calculator">60 + 59 + 57 + 55 + 53 + 51 + 49 + 47 + 45 + 43 + 41 + 39 + 37 + 35 + 33 + 31 + 29 + 27 + 25 + 23 + 21 + 19 + 17 + 15 + 13 + 11 + 9 + 7 + 5 + 3 + 1</gadget>
<output>960</output>

<result>960</result>