The Fibonacci sequence is 1, 1, 2, 3, 5, 8, 13, ..., so what is the difference between the 100th item of the sequence and the sum of the first 98 items?
斐波那契数列为1，1，2，3，5，8，13，…，那么数列的第100项与前98项之和的差是多少．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">2 - 2</gadget>
<output>0</output>

<gadget id="calculator">1 + 0 + 1 + 0 + 2</gadget>
<output>4</output>

<gadget id="calculator">2 - 4</gadget>
<output>-2</output>

<gadget id="calculator">1 + 2 + (-2) + 1 + 2 + (-2) + 2 + 1 + 2</gadget>
<output>7</output>

<gadget id="calculator">8 - 7</gadget>
<output>1</output>

<gadget id="calculator">1 + 1 + 2 + 1 + 2 + 1 + 2 + 2</gadget>
<output>12</output>

<gadget id="calculator">13 - 12</gadget>
<output>1</output>

<result>1</result>