#include<bits/stdc++.h>
using namespace std;
int n,s=0; 
int main(){
cin>>n;
for(int i=2;i*i<=n;i++){
    if(n%i==0) {
        if(i==n/i) s=s+i;
        else s=s+i+n/i;    
    }
} 
 cout<<s;
    return 0;
}
/**************************************************************
	Problem: 1084
	User: chenlingxuan
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/