Determine the valence intensity of the following tweet, considering the mental state of the author. Assign a real number between 0 and 1, where 0 denotes extremely negative and 1 denotes extremely positive.
Tweet: @lennyabrahamson May I send you a copy of #HeroTheGreyhound? Either e-book or real paper one! A boy and a greyhound #smiles #tears
0.677