# Day 25: Spread The Christmas Spirit!

Algebra Level 1

To end this Advent Calendar, let's finish by wishing everyone a Merry Christmas!

At the beginning of Christmas only one person (Santa) has the Christmas Spirit.

At the end of every hour every person with the Christmas Spirit infuses $$3$$ new people with the Christmas Spirit, unless everyone already has the Christmas Spirit. (There is no overlapping; only one person can infuse a specific person.)

Assuming that the world has approximately $$7\ \mathrm{billion}$$ people, will everyone in the world be infused with the Christmas Spirit by the end of the $$24$$ hours of Christmas Day?

(Yes, forget about time zone difference as Christmas Day is obviously relative to Santa time :) )

(If you are being very pedantic, you can assume that the people take it in turns to infuse others at the end of each hour)

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