The sum of the numerator and denominator of a fraction is the largest two-digit prime number. If the numerator is increased by 1, the fraction is equal to 1. What is the fraction?
一个分数分子与分母的和是最大的两位质数，如果分子增加1，那么这个分数就等于1，这个分数是多少？
<gadget id="calculator">97 - 1</gadget>
<output>96</output>

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

<gadget id="calculator">96 / 2</gadget>
<output>48</output>

<gadget id="calculator">48 + 1</gadget>
<output>49</output>

<gadget id="calculator">96 / 2 / 49</gadget>
<output>48/49 = around 0.979592</output>

<result>48/49 = around 0.979592</result>