
Euler's Phi Function
For given integer n, count the totatives of n, that is, the positive integers less than or equal to n that are relatively prime to n.
Input
n
An integer n (1 ≤ n ≤ 1000000000).
Output
The number of totatives in a line.
Sample Input 1
6
Sample Output 1
2
Sample Input 2
1000000
Sample Output 2
400000
