(* read digits until a nondigit and return their value
   assuming i is value of previously read digits
   of digits *)
fun getInt(i,IN) =
        if not (isSome(TextIO.lookahead(IN))) then
            i (* end of file reached *)
        else
            let
                val c = valOf(TextIO.input1(IN))
            in
                if c <= #"9" andalso c >= #"0" then (* c is a digit *)
                    getInt(10*i+ord(c)-ord(#"0"),IN)
                else i
            end;

(* print integer i in decimal *)
fun putInt1(i,OUT) =
        if i<10 then
            TextIO.output(OUT, str(chr(i+ord(#"0"))))
        else (
            putInt1(i div 10, OUT); (* print all but the last digit *)
            putInt1(i mod 10, OUT)  (* print the last digit *)
        );

(* print i, surrounding multidigit numbers by parens *)
fun putInt(i,OUT) =
        if i<10 then
            putInt1(i,OUT)
        else (
            TextIO.output(OUT,"(");
            putInt1(i,OUT);
            TextIO.output(OUT,")")
        );

(* convert i to a sequence of base-b digits and print *)
fun convert1(i,b,OUT) =
        if i<b then putInt(i,OUT) else (
            convert1(i div b, b, OUT);
            putInt(i mod b, OUT)
        );

(* read i and b and print i in base b *)
fun convert(IN,OUT) =
        let
            val i = getInt(0,IN);
            val b = getInt(0,IN)
        in
            convert1(i,b,OUT)
        end;