#Write a function called rabbit_hole. rabbit_hole should have

#two parameters: a dictionary and a string. The string may be

#a key to the dictionary. The value associated with that key,

#in turn, may be another key to the dictionary.

#

#Keep looking up the keys until you reach a key that has no

#associated value. Then, return that key.

#

#For example, imagine if you had the following dictionary.

#This one is sorted to make this example easier to follow:

#

# d = {"bat": "pig", "pig": "cat", "cat": "dog", "dog": "ant",

# "cow": "bee", "bee": "elk", "elk": "fly", "ewe": "cod",

# "cod": "hen", "hog": "fox", "fox": "jay", "jay": "doe",

# "rat": "ram", "ram": "rat"}

#

#If we called rabbit_hole(d, "bat"), then our code should...

#

# - Look up "bat", and find "pig"

# - Look up "pig", and find "cat"

# - Look up "cat", and find "dog"

# - Look up "dog", and find "ant"

# - Look up "ant", and find no associated value, and so it would

# return "ant".

#

#Other possible results are:

#

# rabbit_hole(d, "bat") -> "fly"

# rabbit_hole(d, "ewe") -> "hen"

# rabbit_hole(d, "jay") -> "doe"

# rabbit_hole(d, "yak") -> "yak"

#

#Notice that if the initial string passed in is not a key in

#the dictionary, that string should be returned as the result as

#well.

#

#Note, however, that it is possible to get into a loop. In the

#dictionary above, rabbit_hole(d, "rat") would infinitely go

#around between "rat" and "ram". You should prevent this: if a

#key is ever accessed more than once (meaning a loop has been

#reached), return the boolean False.

#

#Hint: If you try to access a value from a dictionary that does

#not exist, a KeyError will be raised.

#Write your function here!

#Below are some lines of code that will test your function.

#You can change the value of the variable(s) to test your

#function with different inputs.

#

#If your function works correctly, this will originally

#print: ant, hen, doe, yak, False, each on their own line.

d = {"bat": "pig", "pig": "cat", "cat": "dog", "dog": "ant",

"cow": "bee", "bee": "elk", "elk": "fly", "ewe": "cod",

"cod": "hen", "hog": "fox", "fox": "jay", "jay": "doe",

"rat": "ram", "ram": "rat"}

print(rabbit_hole(d, "bat"))

print(rabbit_hole(d, "ewe"))

print(rabbit_hole(d, "jay"))

print(rabbit_hole(d, "yak"))

print(rabbit_hole(d, "rat"))