CF9C Hexadecimal's Numbers

Description

One beautiful July morning a terrible thing happened in Mainframe: a mean virus Megabyte somehow got access to the memory of his not less mean sister Hexadecimal. He loaded there a huge amount of $ n $ different natural numbers from 1 to $ n $ to obtain total control over her energy. But his plan failed. The reason for this was very simple: Hexadecimal didn't perceive any information, apart from numbers written in binary format. This means that if a number in a decimal representation contained characters apart from 0 and 1, it was not stored in the memory. Now Megabyte wants to know, how many numbers were loaded successfully.

Input Format

N/A

Output Format

N/A

Explanation/Hint

For $ n $ = 10 the answer includes numbers 1 and 10.