import math
def divsum(n):
    result=0
    for i in range(2,(int)(math.sqrt(n))+1):
        if(n%i==0):
            if(i==n/i):
                result=result+i
            else:
                result=result+(i+n//i)
    return (result+n+1)
number=int(input())
value=0
for i in range(1,number+1):
    if((divsum(i)/i)-(divsum(i)//i)==float(1/2)):
        value=value+i
print(value)

import java.io.*;
import java.util.*;

public class Solution {

    public static int perfect(long n){
        long sum=n+1;
        for(long i=2;i<=Math.sqrt(n);i++){
            if(n%i==0)
            sum+=i;
        }
        if(sum==n)
        return 1;
        else
        return 0;
    }
    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner sc=new Scanner(System.in);
        long n=sc.nextLong();
        long sum=0;
        for(long i=1;i<=n;i++){
            if(perfect(i)==1){
                long sigma=2*n;
                double p=sigma/n;
                long k=(long)p;
                if(k-p==0.5)
                sum+=i;
            }
        }
        System.out.println(sum);
    }
}