There is a consensus among the knowledgeable reviewers that this is a good paper that addresses one of the important problems. No major concerns was raised during the discussion and the authors provided a rebuttal that helped clarify some of the reviewers' questions. The paper is therefore accepted as poster. Nevertheless, one of the concerns that came up during the discussion is that Assumption 2 seems restrictive in some situations. The authors discussed this limitation in Line 86-87 in the manuscript, but it would improve the paper significantly if the authors could emphasize this limitation from theoretical and practical aspects in their camera-ready version. The reviewers also gave suggestions on how to improve the paper in their reviews. Please also take them into consideration when preparing the camera-ready version.