Program FNG;
Uses crt;
Var n,i: longint;
s: qword;
Function Tinh(a: longint): qword;
Var i: longint;
s: qword;
Begin
s:=1;
For i:=1 to a do
s:=s*a;
Tinh:=s;
End;
Begin
Clrscr;
Write('Nhap n: '); Readln(n);
s:=0;
For i:=1 to n do
s:=s+tinh(i);
Write('S = ',s);
Readln
End.