A 1500-meter-long gravel road is paved, 400 meters are paved on the first day, and 500 meters are paved on the second day. How many meters are left unpaved?
铺一条长1500米的石子路，第一天铺了400米，第二天铺了500米．还有多少米没有铺？
<gadget id="calculator">1_500 - 400 - 500</gadget>
<output>600</output>

<result>600</result>