Because the battery is dead, the clock stops. It is exactly 12:20 at this time. Find the angle between the hour hand and the minute hand.
由于电池没电，时钟停止走动，此时正好是12：20，求时针与分针的夹角多少．
<gadget id="calculator">4 * 30</gadget>
<output>120</output>

<gadget id="calculator">0.5 * 20</gadget>
<output>10</output>

<gadget id="calculator">120 - 10</gadget>
<output>110</output>

<result>110</result>