Why I am failed in Test#3?
Who can help me?


var a:array[2..9] of integer;
i,j,k,l:integer;
n:int64;
begin
  read(n);
  if n=0 then begin writeln('10');exit;end;
  for i:=9 downto 2 do
  while n mod i=0 do begin n:=n div i;a[i]:=a[i]+1;end;
  if n=1 then begin for i:=2 to 9 do
  for j:=1 to a[i] do write(i);end
  else write('-1');
end.

I have same problem. input=1, output=1.