Beautiful Numbers

Problem Description

If all the digits of a positive integer are the same in decimal, Little A thinks the positive integer is beautiful. For example, every digit of $6$ is $6$, so $6$ is beautiful. Every digit of $99$ is $9$, so $99$ is beautiful. The digits of $123$ are not all the same, so $123$ is not beautiful.

Little A wants to know how many beautiful positive integers do not exceed $n$. Can you count them for him?

Input Format

One line containing one positive integer $n$.

Output Format

One line containing one positive integer: the number of beautiful positive integers not exceeding $n$.

Sample Input

Sample Input 1

6

Sample Input 2

2025

Sample Output

Sample Output 1

6

Sample Output 2

28

Sample Explanation

For the first sample, $n = 6$. The positive integers not exceeding $6$ are $1, 2, 3, 4, 5, 6$. All of them are single-digit numbers with identical digits, so they are all beautiful. Therefore there are $6$ beautiful numbers in total, and the output is $6$.

Constraints

For all test cases, $1 \le n \le 2025$.