Longge's problem

Time Limit
1s
Memory Limit
65536KB
Judge Program
Standard
Ratio(Solve/Submit)
0.00%(0/0)
Description:

Longge is good at mathematics and he likes to think about hard mathematical problems which will be solved by some graceful algorithms. Now a problem comes: Given an integer N(1 < N < 2^31),you are to calculate ∑gcd(i, N) 1<=i <=N.

"Oh, I know, I know!" Longge shouts! But do you know? Please solve it.

Input:

Input contain several test case.
A number N per line.

Output:

For each N, output ,∑gcd(i, N) 1<=i <=N, a line

Sample Input:
2
6
Sample Output:
3
15

Submit