#abc193c. [abc193_c]Unexpressed
[abc193_c]Unexpressed
Problem Statement
Given is an integer . How many integers between and (inclusive) are unrepresentable as , where and are integers not less than ?
Constraints
- is an integer.
Input
Input is given from Standard Input in the following format:
Output
Print the answer.
Sample Input 1
8
Sample Output 1
6
and are representable as : we have and .
On the other hand, , , , , , and are unrepresentable as using integers and not less than , so the answer is .
Sample Input 2
100000
Sample Output 2
99634