#include<iostream.h>
#include<fstream.h>
#include<string.h>
int ridica(int a)
{int i,p=1;
	for(i=1;i<=a;i++)
	p=p*a;
	return p;}

int main()
{int t,i,j,s=0;
//char a[100];
int a;
ifstream f("cifra.in");
ofstream h("cifra.out");
cin>>a;
for(i=1;i<=a;i++)
	s=s+ridica(i);
cout<<s;
return 0;}