#include <bits/stdc++.h>
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define mp make_pair
#define pb push_back
#define sz size
#define for(i, a, b) for (int i = (a); i <= (b); i++)
const int N = 1e5, INF = 1e9, MOD = 1e7;
using namespace std;
void fast()
{
        #define taskname "test1"
        if(fopen(taskname".inp","r"))
        {
            freopen(taskname".inp","r",stdin);
            freopen(taskname".out","w",stdout);
        }
        cin.tie(0)->sync_with_stdio(0);
}
int main() {
    fast();
    ll n,tonguoc=0;
    cin>>n;
    for(i,1,sqrt(n)){
        if(n%i==0)
        {
            tonguoc+=i;
            if(n/i!=i) tonguoc+=n/i;
        }
    }
    cout<<tonguoc;
    return 0;
}