An engineering team repairs a 56-kilometer-long road. On the first day, the full length (1/4) is repaired, and on the second day, the full length (2/7) is repaired. How many kilometers of this road are left to be repaired?
某工程队修一条56千米长的公路，第一天修了全长的(1/4)，第二天修了全长的(2/7)，这条公路还剩多少千米没有修？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (1/4) - (2/7)</gadget>
<output>13/28 = around 0.464286</output>

<gadget id="calculator">56 * (13/28)</gadget>
<output>26</output>

<result>26</result>