A 400-meter-long bridge is hung with colorful lights on both sides, and every two are 4 meters apart. How many lights are hung from the bridge head to the end of the bridge?
一座长400米的大桥两旁挂彩灯，每两个相隔4米，从桥头到桥尾一共挂了多少盏灯？
<gadget id="calculator">400 / 4</gadget>
<output>100</output>

<gadget id="calculator">100 + 1</gadget>
<output>101</output>

<result>101</result>