var n:longint;
    i,j:byte;
    a:array[2..9] of byte;
begin
  fillchar(a,sizeof(a),0);
  readln(n);
  if (n=1) then begin writeln('1');halt end;
  if (n=0) then begin writeln('10');halt end;
  while ((n mod 2)=0) do
  begin
    a[2]:=a[2]+1;
    n:=n div 2;
  end;

  while ((n mod 3)=0) do
  begin
    a[3]:=a[3]+1;
    n:=n div 3;
  end;

  while ((n mod 5)=0) do
  begin
    a[5]:=a[5]+1;
    n:=n div 5;
  end;

  while ((n mod 7)=0) do
  begin
    a[7]:=a[7]+1;
    n:=n div 7;
  end;
  if (n<>1) then writeln('-1')
  else
  begin
    a[8]:=a[2] div 3;
    a[2]:=a[2] - a[8]*3;
    a[9]:=a[3] div 2;
    a[3]:=a[3] - a[9]*2;
    if ((a[2]=2) and (a[3]=1)) then
    begin
      a[6]:=a[6]+1;
      a[2]:=a[2]-1;
      a[3]:=a[3]-1
    end
    else if ((a[2]=1) and (a[3]=1)) then
    begin
      a[6]:=a[6]+1;
      a[2]:=a[2]-1;
      a[3]:=a[3]-1
    end
    else if ((a[2]=2) and (a[3]=0)) then
    begin
      a[4]:=a[4]+1;
      a[2]:=a[2]-2;
    end
  end;
  for i:=2 to 9 do for j:=1 to a[i] do write(i);
  writeln;
end.

you must start with
  n mod 9
then
  n mod 8
then
  n mod 7
...
  n mod 2