How many different selection methods are there for selecting two different types of calligraphy works from 5 pieces of regular script, 3 pieces of official script and 2 pieces of cursive script?
从5幅楷体，3幅隶书，2幅草体书法作品中选取不同类型的两幅，共有多少种不同的选法．
<gadget id="calculator">15 + 10 + 6</gadget>
<output>31</output>

<result>31</result>