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

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

        val regularTime = (a + b - 1) div b
        val duringPromotion = (a + c - 1) div c

        val ans = if duringPromotion <= regularTime * 2 div 3
                  then "YES"
                  else "NO"
    in
        print (ans ^ "\n")
    end