For a positive integer , let be the sum of all divisors of , so e.g. .
A perfect number, as you probably know, is a number with .
Let us define the perfection quotient of a positive integer as .
Find the sum of all positive integers for which has the form , where is an integer.
Input Format
The only line of input contains integer .
Constraints
Output Format
Print the only line with the answer.
Sample Input 0
10
Sample Output 0
2
Explanation 0
The only suitable number from to is .
.
Sample Input 1
100
Sample Output 1
26
Explanation 1
is the next suitable number after . There are no other suitable numbers between and .