Euler's Totient Function
Compute \(phi(n)\), the number of integers from \(1\) through \(n\) that are coprime with \(n\).
Input
One line containing \(n\).
The input satisfies:
- \(1 \le n \le 10^12\)
Output
Print \(phi(n)\).
Example
Input
15845
Output
12672
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