#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;


vector<ll> primes(ll n){
    vector<ll> ans;
    vector<bool> isprime(n+1,true);

    for(int i=2;i<=n;i++){
        if(!isprime[i])continue;
        else{
            ans.push_back(i);
            for(int j=2;j<=n/i;j++){
                isprime[i*j]=false;
            }
        }
    }

    return ans;
    
}
int main()
{
    vector<ll> ps=primes(100000);
    ll n;
    cin>>n;
    ll n0=n;
    ll ans=1;
    for(ll x:ps){
        if(n%x==0){
            ll cnt=1;
            while(n%x==0){
                n/=x;
                cnt++;
            }
            ans*=cnt;
        }
    }
    if(n>1)ans*=2;
    cout<<n0-ans<<endl;
    

    return 0;
}