basket of apples has 3 numbers of 3, 7 numbers of 7, and there is 1 remaining in the end. What is the minimum number of apples in this basket?
一筐苹果3个3个的数，7个7个的数，最后都余1个，这筐苹果最少是多少个．
<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">21 + 1</gadget>
<output>22</output>

<result>22</result>