The teacher wants to distribute 25 identical apples to 5 children, and each child is required to get at least 4 apples. How many different distribution methods are there in total?
老师要将25个相同的苹果分给5个小朋友，要求每个小朋友至少分得4个苹果，总共有多少种不同分配的方法．
<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<result>21</result>