#AC2565. Longge
Longge
题目描述
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<231),you are to calculate ∑gcd(i,N)
"Oh, I know, I know!" Longge shouts! But do you know? Please solve it.
输入格式
Input contain several test case.
A number N per line.
输出格式
For each N, output ,∑gcd(i,N) 1≤i≤N, a line
样例
2
6
3
15