A construction team builds a section of road. (1/4) repaired this road in the first week, and (2/7) repaired this road in the second week. In the second week, I repaired 2 kilometers more than the first week. How long is this road in kilometers?
某工程队修筑一段公路．第一周修了这段公路的(1/4)，第二周修了这段公路的(2/7)．第二周比第一周多修了2千米．这段公路全长多少千米？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

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

<gadget id="calculator">(2/7) - (1/4)</gadget>
<output>1/28 = around 0.035714</output>

<gadget id="calculator">2 / (1/28)</gadget>
<output>56</output>

<result>56</result>