In ***X-Men: The Last Stand***, we saw that Wolverine kills Jean Grey and Scott Summers was killed. Later, In ***The Wolverine***, Logan recovers from his past. However, in ***X-Men: Days of Future Past***, Scott Summers and Jean Grey were there (who were killed in Last Stand). This movie is the sequel of ***X-Men Last Stand***. If this is so, then why does X-Men: Days of Future Past show Jean and Scott alive? Where does the timeline of both movies lie exactly?