Priyanka Chopra on her role in "Barfee"

After creditably essaying seven looks in "7 Khoon Maaf" and 12 different characters in "What's Your Raashee?", Priyanka Chopra will be seen as a mentally-challenged girl in her upcoming film "Barfee", which she describes as "by far the most challenging role"."I have started shooting for the film, have shot nearly five days till now. I must admit that it is quite a difficult task," said Priyanka,