puzzle : there is a island and the resident are either blue or black eyed. The residents are trapped in the island and want to leave. One day a foreigner comes and says there are few blue eyed people. He will be sending a steamer to the island every day and blue eyed people can leave. But if a black eyed person approaches the steamer, he will be killed. Constraint: No body knows their eye colour and can't even ask or say the colour to any other person. even cant see their reflection. So how many days is required for all the blue eyed person to leave the island.
