In this task, you are given two phrases: Head and Tail, separated with <sep>. The Head and the Tail events are short phrases possibly involving participants. The names of specific people have been replaced by generic words (e.g., PersonX, PersonY, PersonZ). PersonX is always the subject of the event. You have to determine whether the Head happens before the Tail or not. Classify your answers into "Yes" and "No". The phrase may also contain "___", a placeholder that can be an object, a person, and/or an action.

Ex Input:
Head: PersonX adapts to PersonY's environment<sep>Tail: becomes more flexible

Ex Output:
No


Ex Input:
Head: PersonX keeps PersonY in touch<sep>Tail: PersonX talks to him over facebook to see what he's doing

Ex Output:
Yes


Ex Input:
Head: PersonX activates a shadow over everyone<sep>Tail: don't get as much sun.

Ex Output:

No