The factory processes a batch of parts, processing (1/7) of the total in the first week, processing (1/4) of the total in the second week, and processing in the third week is equivalent to the sum of the previous two weeks, leaving a fraction How much is not processed?
工厂加工一批零件，第一周加工了总数的(1/7)，第二周加工了总数的(1/4)，第三周加工的相当于前两周的和，还剩几分之几没有加工？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

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

<gadget id="calculator">(1/7) + (1/4) + (1/7) + (1/4)</gadget>
<output>11/14 = around 0.785714</output>

<gadget id="calculator">1 - (11/14)</gadget>
<output>3/14 = around 0.214286</output>

<result>3/14 = around 0.214286</result>