Huanhuan starts from 100 and counts up by adding 3 each time (100, 103, ...), welcomes starting from 500 and counts down by subtracting 5 each time (500, 495, ...), if two people count The speed is the same, both of them will count out the same number at the same time, what is the same number.
欢欢从100开始，以每次加3往上数数(100，103，…)，迎迎从500开始，以每次减5往下数数(500，495，…)，如果两人数数的速度相同，他们两人将同时数出一个相同的数，请问，这个相同的数是多少．
<gadget id="calculator">500 - 100</gadget>
<output>400</output>

<gadget id="calculator">3 + 5</gadget>
<output>8</output>

<gadget id="calculator">400 / 8</gadget>
<output>50</output>

<gadget id="calculator">3 * 50</gadget>
<output>150</output>

<gadget id="calculator">100 + 150</gadget>
<output>250</output>

<result>250</result>