a is a natural number not equal to 0, the largest result of the following formula is a+how much
a是不为0的自然数，下列式子结果最大的是a+多少
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>