include
using namespace std; int i,n,f,sum; int main () { f=1; cin>>n; for (i=1;i<=n;i++) { f=f*i; sum=sum+f; } cout<<sum; return 0; }
using namespace std; int i,n,f,sum; int main () { f=1; cin>>n; for (i=1;i<=n;i++) { f=f*i; sum=sum+f; } cout<<sum; return 0; }