How many roles does Peter Sellers have in the 1964 film "Dr Strangelove"?

Explanation

Peter Sellers (1925-1980) was born in England and is considered one of the most talented comedians ever. In his relatively short career he managed to make both films and theatre. He is probably most well-known for his role in "The Pink Panther" where he plays an incompetent detective. He has also played more serious roles however - he has a major part in "Lolita" from 1962, and plays three parts in "Dr Strangelove" from 1964. Both films are directed by Stanley Kubrick. Sellers has been nominated for three Academy Awards but never died. He died only 54 years old and his sense of humour extended to his own funeral - where Glenn Miller's song "In The Mood", a song he hated, was played.