#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)

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

    ll ans = 0LL;
    for(ll i = 1; i*i <= N; ++i){
        if(N % i != 0LL) continue;
        ans += i;
        if(i*i != N) ans += (N/i);
    }
    cout << ans << endl;

    return 0;
}