#abc103c. [abc103_c]Modulo Summation
[abc103_c]Modulo Summation
Problem Statement
You are given positive integers .
For a non-negative integer , let .
Here, denotes the remainder of the division of by .
Find the maximum value of .
Constraints
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
Output
Print the maximum value of .
Sample Input 1
Sample Output 1
is the maximum value of .