G. Who Likes Mathematics is not Boki-chan
time limit per test
1 second
memory limit per test
1024 megabytes
input
standard input
output
standard output

Boki-chan indeed does not like mathematics, so he hopes to find some numbers he likes from a given range.

If the absolute difference of all adjacent digits of a number is $$$1$$$, then Boki-chan will like it. In particular, all one-digit numbers are liked by Boki-chan. For example, Boki-chan likes $$$4567$$$, $$$4565654$$$, $$$3210$$$, $$$9$$$, but does not like $$$112$$$, $$$12332$$$, $$$555$$$.

Given the interval $$$[L, R]$$$, please find the number of numbers that Boki-chan likes within this interval.

Input

Input a line with two integers $$$L, R (1 \leq L \leq R \leq 10^{18})$$$, representing the given interval.

Output

Output a line with a single integer, representing the number of numbers that Boki-chan likes in $$$[L, R]$$$.

Example
Input
6 21
Output
7
Note

In the first sample, the $$$7$$$ numbers that satisfy the condition are: $$$6$$$, $$$7$$$, $$$8$$$, $$$9$$$, $$$10$$$, $$$12$$$, $$$21$$$.