2014. Голова профессора Интегралова

program faktor;
var
I:integer;
F,N,S:int64;
begin
Assign (input,'input.txt');
Reset (input);
readln (N);
F:=1;
for I:=1 to N do
  F:=F*I;
S:=0;
while (F>9) do
   begin
      while (F>0)do begin
        S:=S+ F mod 10;
        F:= F div 10;
      end;
  F:=S;
  S:=0;
  end;
Assign (output,'output.txt');
Rewrite(output);
Write (F);
Close (input);
Close (output);
end.
___________________________________________________________________________

var

N,S: integer;

F: longint;

function fak (A:integer) : longint;

begin

if (A=0) or (A=1) then fak :=1 else

  Fak:=A*fak(A-1);

end;

function Sum(S:integer): integer;

var S1: integer;

begin

S1:=0;

while S>0 do

  begin

    S1:=S1 + S mod 10;

    S:= S div 10;

  end;

Sum:=S1;

end;

begin

  Read (N);

  F:= fak (N);

  Writeln (F);

  S:=Sum(f);

  //Writeln (S);

  While S>9 do

    begin

    S:=Sum(S);

    Writeln (S);

    end;

end.