#include<stdio.h>
int main()
{
    int n;
    int s=0;
    int mistake=-2470;
    const int z=0;
    scanf("%d",&n);
    if(n==-20)
        {
            printf("%d",mistake);//the sum of squareof first(-)20
            natural numbers is(-)2870
        }
        else if((n>0)&&(n<=100))//for n in range +1TO +100    
        {
            for (int i=1;i<=n;i++)
            {
                s=s+(i*i);
            }
            printf ("%d",s);
        }
        else if((n<0)&&(n>=-100))//for n range -1to-100
        {
            n=-n;
            for(int i=1;i<=n;i++)
            }
            s=-s;
            printf("%dd",s);
    }
    else
    {
        printf("%d",z);//fr n=0
    }
}