Palindrome-Free Numbers

문제

A string is a palindrome if it remains the same when it is read backwards. A number is palindrome-free if it does not contain a palindrome with a length greater than 1 as a substring. For example, the number 16276 is palindrome-free whereas the number 17276 is not because it contains the palindrome 727.

Your task is to calculate the total number of palindrome-free numbers in a given range.

입력

The input contains two integers, a and b. (0 ≤ a ≤ b ≤ 10¹⁸)

출력

The output should contain one integer: the total number of palindrome-free numbers in the range a, ..., b (including a and b).