A, B, C, and D build a 2,400-meter-long road. A builds the other three (1/2), B builds the other three (1/3), and C builds the road. (1/4) of the other three people asked: How many meters did Ding Xiu have? ．
甲、乙、丙、丁四人修一条长2400米长的公路，甲修的是其他三人的(1/2)，乙修的是其他三人的(1/3)，丙修的是其他三人的(1/4)，问：丁修了多少米？．
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + 4</gadget>
<output>5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/3) - (1/4) - (1/5)</gadget>
<output>13/60 = around 0.216667</output>

<gadget id="calculator">2_400 * (13/60)</gadget>
<output>520</output>

<result>520</result>