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


val () =
    let
        val n = readInt ()
        val a = readInt ()
        val b = readInt ()
        val c = readInt ()

        fun findAns 0 = 0
          | findAns x = if x mod a = 0 orelse x mod b = 0 orelse x mod c = 0
                        then 1 + findAns (x - 1)
                        else findAns (x - 1) 

        val ans = findAns n
    in
        print (Int.toString ans ^ "\n")
    end