#include<iostream>
#include<cmath>
using namespace std;
int main() {
long long n;
cin>>n;
long long sum=0;
for (int i =1; i <=sqrt(n); i++) {
if(n % i == 0) {
sum=i+sum;
}
if(i!=n/i){
sum+=n/i;
}
}cout<<sum;
}
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