Pascal Factorial

program factorial;
 uses wincrt;
 var
    n,fak,i: integer;
 begin
 clrscr;
        write('n=');readln(n);
        fak:=1;
        for i:= 1 to n do
        fak:= fak * i;
        writeln('fak=',fak);
 readln;
 end.