#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const ll INF = 1ll<<30;
const ll longINF = 1ll<<60;
const ll MOD = 1000000007;
const double EPS = 1e-9;
const bool debug = 0;
//---------------------------------//

int main() {
	ll N;
	cin >> N;
	
	ll ans = 0;
	for (ll i = 1; i * i <= N; i++) if (N % i == 0) {
		ans += i;
		if (i * i != N) ans += N / i;
	}
	
	cout << ans << endl;
	return 0;
}