You are given a positive integer n.
For every integer x from 1 to n, we write down the integer obtained by removing all zeros from the decimal representation of x.
Return an integer denoting the number of distinct integers written down.
Example 1:
Input: n = 10
Output: 9
Explanation:
The integers we wrote down are 1, 2, 3, 4, 5, 6, 7, 8, 9, 1. There are 9 distinct integers (1, 2, 3, 4, 5, 6, 7, 8, 9).
Example 2:
Input: n = 3
Output: 3
Explanation:
The integers we wrote down are 1, 2, 3. There are 3 distinct integers (1, 2, 3).
Constraints:
1 <= n <= 1015