An engineering team repaired a road, and repaired (1/3) kilometers in the first week, (2/9) kilometers in the second week, and (1/6) kilometers less than the sum of the previous two weeks in the third week ． How many kilometers did you repair in the third week?
某工程队修一条路，第一周修了(1/3)千米，第二周修了(2/9)千米，第三周修的比前两周的总和少(1/6)千米．第三周修了多少千米？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(1/3) + (2/9)</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(5/9) - (1/6)</gadget>
<output>7/18 = around 0.388889</output>

<result>7/18 = around 0.388889</result>