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

val () =
    let
        val n = readInt ()
        val a_s = List.tabulate (n - 1, fn _ => readInt ())

        val sum = List.foldl (fn (a, acc) => a + acc) 0 a_s

        val ans = List.foldl (fn (a, acc) =>
                                 if (sum + a) mod n = 0 then acc + 1
                                 else acc)
                             0
                             (List.tabulate (101, fn i => i))
    in
        print (Int.toString ans ^ "\n")
    end