To celebrate the 60th anniversary of the National Day, the students in Class 1 of the fourth grade are going to make some five-star red flags with red and yellow paper. For this reason, the students in this class bought red paper and yellow paper, and the monitor distributed 6 red papers and 15 yellow papers to each student on average. Please calculate how many sheets of the two kinds of paper you bought in this class?
四年级一班的同学为庆祝国庆60周年，准备用红纸和黄纸做一些五星红旗．为此，该班同学们买来了红纸和黄纸，由班长平均发给每一个同学6张红纸、15张黄纸，发给18个同学后，忽然发现还剩122张．请你计算这个班两种纸一共买了多少张？
<gadget id="calculator">18 * 6</gadget>
<output>108</output>

<gadget id="calculator">18 * 15</gadget>
<output>270</output>

<gadget id="calculator">108 + 270 + 122</gadget>
<output>500</output>

<result>500</result>