Use the five numbers 1, 2, 3, 4, 5 to form a four-digit number without repeated numbers, how many of them are even numbers.
用1、2、3、4、5这五个数字组成不含重复数字的四位数，其中偶数有多少个．
<gadget id="calculator">2 * 4 * 3 * 2</gadget>
<output>48</output>

<result>48</result>