#include <vector>
#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <math.h>
#include <map>
using namespace std;

long long yakusu_sum(long long x){
	if(x==1){
		return 1;
	}
	long long sum=0;
	for(long long i=1;i*i<=x;i++){
		if(x%i==0){
			sum+=i;
			if(x/i==i)continue;
			sum+=x/i;
		}
	}
	return sum;
}

int main(){
	long long n;
	cin >> n;
	cout << yakusu_sum(n) << endl;
	return 0;
}