1/2,2/1-(two rows with two digits are 3, and the numerator is the second in the row), and the sum of the numerator and denominator is 3.
1/3, 2/2, 3/ 1- (three rows and three places, with the numerator ranking third) The sum of denominator is 4.
1/4, 2/3, 3/2, 4/ 1- (four rows, the numerator is the fourth in the row), and the sum of denominator is 5.
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The sum of 3/7 numerator and denominator is 10, so in the ninth line, the denominator is 9, so1/9,2/8,3/7. ...
3/7 is the third in the ninth line, and the first eight lines of * * have 1+2+3+4+5+6+7+8=36 bits plus 3 bits, which is the 39th.