#include<stdio.h>
int main(){
    int a,b,i;
    scanf("%d",&a);
    if (a<0){
        for (i=0;i<=a;i++){
            b=b+(i*i);
        }   
        printf("%d",b);
    {else 
        for (i=0;i<=a;i++){
            b=b+(i*i);
        }   
        printf("%d",b);
}