• problem with the example

Question related to mission Ghosts Age

 

Hi

I didn't get the example

A newborn ghost -- 10000 units of opacity.
1 year -- 10000 - 1 = 9999 (1 is a Fibonacci number).
2 year -- 9999 - 2 = 9997 (2 is a Fibonacci number).
3 year -- 9997 - 3 = 9994 (3 is a Fibonacci number).
4 year -- 9994 + 1 = 9995 (4 is not a Fibonacci number).
5 year -- 9995 - 5 = 9990 (1 is the Fibonacci number). <<<<<<<<< why 1 ??? it should be 5