Rana Mitter talks to Tony Harrison, the winner of the biennial David Cohen prize - one of our most prestigious literary awards. Two other writers join Rana - Ru Freeman and Romesh Gunesekara. Both from Sri Lanka and both on the programme to discuss the role of the writer in a country recovering from civil war. Finally, as part of the BBC's Get Creative initiative, the mathematician, Marcus du Sautoy, will be explaining why he values the arts as much as numbers.