There is a column of fractions: (1/1);(1/2);(2/2);(1/3);(2/3);(3/3);(1/4);(2/4 );(3/4);(4/4);...What is the 1998th number?
有一列分数：(1/1)；(1/2)；(2/2)；(1/3)；(2/3)；(3/3)；(1/4)；(2/4)；(3/4)；(4/4)；…其中第1998个数是多少．
<gadget id="calculator">63 * 64</gadget>
<output>4_032</output>

<gadget id="calculator">4_032 / 2</gadget>
<output>2_016</output>

<gadget id="calculator">2_016 - 63</gadget>
<output>1_953</output>

<gadget id="calculator">1_998 - 1_953</gadget>
<output>45</output>

<gadget id="calculator">45 / 63</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>