Question Statement :

Boxes numbered 1, 2, 3, 4 and 5 are kept in a row, each of which are to be filled with one ball, either a red one or a blue one. No two adjacent boxes can be filled with blue balls. Then how many different arrangements are possible, given that all balls of the same colour are exactly identical in every respects?

Type in your answer as an integer. For example, if your answer is 2, type in 2