In a basket of eggs, there are 4 numbers of 4 and 5 numbers of 5. How many eggs are there at least in this basket?
一篮鸡蛋，4个4个的数，5个5个的数都正好数完，这篮鸡蛋至少有多少个？
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<result>20</result>