#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<n; ++i)
#define repl(i,m,n) for(ll i=m; i<n; ++i)

vector<ll> divisor(ll N){
    vector<ll> divi;
    for(ll i = 1LL; i*i <= N; ++i){
        if(N % i == 0LL){
            divi.push_back(i);
            if(i*i != N) divi.push_back(N/i);
        }
    }
    return divi;
}

int main(){
    ll N;
    cin >> N;

    vector<ll> d = divisor(N);
    cout << reduce(d.begin(), d.end(), 0LL) << endl;

    return 0;
}