The set of all positive integers that satisfy the following conditions is S.

"Each number is different from each other, and the sum of any two numbers is not 9."

However, the element of S is expressed in the decimal decimal. Also, a positive integer of 1 digit is included in S.

At this time, answer the next question.

(1) How many of the S elements are exactly 4 digits?

(2) Count from the smaller one and find the element of the 2000th S.