program productofdigits;
 var a:array[2..9] of word;
     n:longint;
     i,k:word;
    begin
    Readln(n);
    for i:=2 to 9 do a[i]:=0;
    if n=0 then write(10) else
     if n=1 then write(1) else begin
        for i:=9 downto 2 do
          while n mod i = 0 do begin n:=n div i; inc(a[i]); end;
      if n<>1 then write(-1) else
          for i:=2 to 9 do
              for k:=1 to a[i] do
          write(i);
    end;
    end.