#include<bits/stdc++.h>
using namespace std;
long long ct;
int main(){
	int n;
	cin>>n;
	for(int i=1;i<=n;i++){
		if(n%i==0){
			ct+=i;
		}
	}
	cout<<ct<<endl;
	return 0;
}
//1 5
//6*5-24=6
//2 4 5 8 10 16 20 25 40
//50 80 100 125  200
//250400
//500 625 1000 1250 2000 2500 5000