fun readInt () =
    valOf (TextIO.scanStream (Int.scan StringCvt.DEC) TextIO.stdIn)


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 = readInt ()
        val s = readStr ()

        val ans = String.substring(s, 1, n - 2)
    in
        print (ans ^ "\n")
    end