package main

import . "fmt"
import . "math/big"

func main() {
	var n int
	Scan(&n)
	// 10^k = 1 (mod n) ?? Euler's totient function??
	r := NewRat(int64(n), 1)
	t := make([]bool, 1e5)
	one := NewRat(1,1)
	x := n
	for i := 2; i*i<=x; i++ {
		if t[i] || x%i != 0 {
			continue
		}
		for x % i == 0 {
			x /= i
		}
		r.Mul(r, new(Rat).Sub(one, NewRat(1, int64(i))))
		for j := i+i; j < len(t); j += i {
			t[j] = true
		}
	} 
	if x > 1 {
		r.Mul(r, new(Rat).Sub(one, NewRat(1, int64(x))))
	}
	Println(r.Num())
}