C :

#include<stdio.h>
#define maxn 100000+1000
int main(){
	long long int n,s;
	while(scanf("%lld",&n)!=EOF){
		s = n * (n+1) * (2 * n +1)/6;
		printf("%lld\n",s);
	}
    return 0;
} 

C++ :

#include<stdio.h>
int main(){
	long long int  n,s;
	while(scanf("%lld",&n)!=EOF){
		s = n * (n+1) * (2 * n +1)/6;
		printf("%lld\n",s);
	}
    return 0;
}