/DAYSO9 - Dãy số

              Uses Crt;
        Var i:longint; n:int64;
                a:array[-1..10000] of longint;
        Function Rev (x:longint):longint;
        var i,res:longint; st1,st:ansistring;
        begin
            str(x,st); st1:=''; //writeln(st,'+');
            for i:=1 to length(st) do st1:=st[i]+st1;
            val(st1,res);
            exit(res);
        end;
        Begin
            //for j:=1 to 1000 do begin n:=j;
            readln(n);
            a[0]:=0; a[-1]:=1; dec(n,2);
            for i:=0 to 110 do a[i]:=rev(a[i-1])+2;
            write(a[n mod 81],' ');
            readln;
        End.
        //cac chu so duoc lap lai do so n khi dao vi tri co the ra so nho hon
        //cac so lap lai tu so 3 tro di
        //co 81 so bi lap lai