11.

uses crt;
var n: longint;

function S(n: longint): int64;
var i, j, ret: int64;
begin
    j:=1; ret:=0;
    for i:=1 to n do begin
        j:=j * i;
        inc(ret, j);
    end;
    exit(ret);
end;

begin
    clrscr;
    readln(n);
    writeln(S(n));
readln;
end.

33.

uses crt;
var n: longint;

function prime(n: longint): boolean;
var i: longint;
begin
    if n < 2 then exit(false);
    for i:=2 to trunc(sqrt(n)) do
        if n mod i = 0 then exit(false);
    exit(true);
end;

begin
    clrscr;
    readln(n);
    writeln(prime(n));
readln;
end.

11.

uses crt;
var n,i,j,res:longint;
begin
clrscr;
readln(n);
for i := 1 to n do
 for j := 1 to i do
   res := res + (i*j); 
writeln(res);
readln;
end.

31.

uses crt;
var n,i:longint;
begin
clrscr;
readln(n);
if n < 2 then
  begin
    writeln(n,' khong phai la so nguyen to');
    readln;
    exit;
  end;
for i := 2 to n-1 do
 if n mod i = 0 then
   begin
     writeln(n,' khong phai la so nguyen to');
     readln;
     exit;
   end;
writeln(n,' la so nguyen to');
readln;
end.