A and B are two different non-zero natural numbers less than 100, what is the maximum value of ((AB)/(A+B)).
A和B是小于100的两个非零的不同自然数，((A-B)/(A+B))的最大值多少．
<gadget id="calculator">99 - 1</gadget>
<output>98</output>

<gadget id="calculator">99 + 1</gadget>
<output>100</output>

<gadget id="calculator">98 / 100</gadget>
<output>49/50 = around 0.98</output>

<result>49/50 = around 0.98</result>