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