The library has 260 story books, 380 science books, and 120 more composition books than the sum of story books and science books. How many composition books are there?
图书馆有故事书260本，有科技书380本，作文书比故事书与科技书的总和还多120本，作文书有多少本？
<gadget id="calculator">260 + 380 + 120</gadget>
<output>760</output>

<result>760</result>