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



val () =
    let
        val a = readInt ()
        val b = readInt ()
        val numOfNotPaired = Int.abs ((a + 1) - b)
    in
        (
          if a + 1 <= b then print "YES\n"
          else print "NO\n";
          print (Int.toString numOfNotPaired ^ "\n")
        )
    end