BRUSSELS (Reuters) - Greece and its international creditors must discuss the Greek crisis as "adults", IMF Managing Director Christine Lagarde said on Thursday. "We can only arrive at a resolution if there is a dialogue, and for the moment we are short of the dialogue, so the key emergency in my view is to restore the dialogue with adults in the room," Lagarde told a news conference. (Reporting by Robin Emmott, editing by Jan Strupczewski)