Observe the arrangement of the following numbers 1 / 1 1 / 2 2 / 1 1 / 3 2 / 2 3 / 1 1 / 4 2 / 3 3 / 2 4 / 1 1 / 5 The rule is that the denominator is one 2,1 3,2,1 4,3,2,1 . Molecule: 1 1,2 1,2,3 1,2,3,4 . 1. But the m-th number from the left is f (m). When f (m) is 2 / 2001, find the product of the value of M and the m-th number 2. In this column of numbers, the number without reduction and denominator 2 is denoted as C, and the one digit after it is denoted as D. whether there are these two numbers C and D, so that CD = 2 001 000. If there are, find out C and D. if not, please explain the reason

Observe the arrangement of the following numbers 1 / 1 1 / 2 2 / 1 1 / 3 2 / 2 3 / 1 1 / 4 2 / 3 3 / 2 4 / 1 1 / 5 The rule is that the denominator is one 2,1 3,2,1 4,3,2,1 . Molecule: 1 1,2 1,2,3 1,2,3,4 . 1. But the m-th number from the left is f (m). When f (m) is 2 / 2001, find the product of the value of M and the m-th number 2. In this column of numbers, the number without reduction and denominator 2 is denoted as C, and the one digit after it is denoted as D. whether there are these two numbers C and D, so that CD = 2 001 000. If there are, find out C and D. if not, please explain the reason

You can find that the product of each line is always 1. Because the numbers at the two ends of each line are reciprocal, and then one bit inside each line is also reciprocal. So when f (m) is 2 / 2001, the product of the lines whose denominator is 2001 is 1. The product of M numbers is 1 × 1 / 2002 × 2 / 2001 = 1 / 2