4 boys and 4 girls participate in a singing competition. They sing one after another. If it is assumed that the two girls cannot sing together and must be separated, how many different orders can they be arranged in?
4个男孩和4个女孩参加歌唱比赛，他们一个接着一个地唱，如果假定两个女孩不能连着唱，必须隔开，那么能排成多少种不同的顺序．
<gadget id="calculator">4 * 3 * 2 * 1</gadget>
<output>24</output>

<gadget id="calculator">24 * 24</gadget>
<output>576</output>

<gadget id="calculator">576 + 576</gadget>
<output>1_152</output>

<result>1_152</result>