Make a program that asks for peoples ages.  The data ends when the age -1 is entered.

Print the list of all ages
Print the list of everyone who is 21 or older (which might be empty)

Print the number of beers to buy (each adult drinks 3)
Print the number of Cokes to buy (each kid drinks 2)
Print the number of brats to buy (adults get 2, kids get 1)

Make sure your program works even if they enter no data.
Make sure your program works even if they enter only one age.

You must use at least three functions.
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The Collatz function works like this:
   collatz(n) = 3n+1 if N is odd
   collatz(n) = n/2 if N is even
   
The collatz sequence is just iterating that formula over and over.

You must make a method called collatz(n) that returns a list with n's collatz sequence

So 
collatz(1) = [1]
collatz(2) = [2,1]
collatz(3) = [3,10,5,16,8,4,2,1]
collatz(4) = [4,2,1]
collatz(5) = [5,16,8,4,2,1]


For every number 1..100, print the collatz sequence
Tell me which number has the longest collatz sequence.  For the range 1..5 it's 3.
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Due Jan 31