A movie theater has 100 seats for ticket A and 200 seats for ticket B, where A ticket is 30 yuan each and B ticket is 10 yuan each. The box office revenue of a certain movie is 4,700 yuan. How many people are there at least in this movie?
某影院有甲票座位100个，乙票座位200个，其中甲票每张30元，乙票每张10元．某场电影票房的收入是4700元，本场观众最少有多少人？
<gadget id="calculator">30 * 100</gadget>
<output>3_000</output>

<gadget id="calculator">4_700 - 3_000</gadget>
<output>1_700</output>

<gadget id="calculator">1_700 / 10</gadget>
<output>170</output>

<gadget id="calculator">100 + 170</gadget>
<output>270</output>

<result>270</result>