Note

This problem was created as the problem for day 12 of Advent Calendar Contest Advent Calendar 2015 and was published on December 12, 2015.

Please watch over it with lukewarm eyes.

Problem Statement

For positive integers $A, B(A \leq B)$, Rian-kun considered the string formed by concatenating the numbers from $A$ to $B$ in decimal notation, and decided to name it the "$(A,B)$ string".

For example, the "$(3,5)$ string" is "$345$", the "$(8,13)$ string" is "$8910111213$", and the "$(102,102)$ string" is "$102$".

Now Rian-kun has become curious about the number of contiguous substrings "$12$" contained in the "$(A,B)$ string" formed from given positive integers $A, B$.

Rian-kun, drunk from his first sip of booze, is in no state to do it, so please find in his place the number of "$12$" contained in the "$(A,B)$ string".

Input

$A$ $B$

The positive integers $A, \ B \ (1 \leq A \leq B \leq 12^{12} (= 8,916,100,448,256))$ that form the "$(A, B)$ string" are given on one line, separated by a space.

Output

Output the number of "$12$" contained in the "$(A,B)$ string" on one line.

Print a newline at the end.

Sample

8 13

1

102 102

0

19951212 20151212

33124

1212 121212121212

15240281554