fun readStr () =
    let
        fun scan reader stream = SOME (StringCvt.splitl (not o Char.isSpace) reader (StringCvt.skipWS reader stream))
    in
        valOf (TextIO.scanStream scan TextIO.stdIn)
    end



val () =
    let
        val n = readStr ()
    in
        if n = "0" then print "0\n"
        else print (n ^ "0\n")  
    end