# Fibonacci is a sequence that starts with 0 and 1
# Every number in the sequence is the sum of the previous 2 numbers
# 0 1 1 2 3 5 8 13 21 34 55

# this function will look for the number in the sequence at an index specified by the user and return it
def fibonacci(index):
	# start the sequence with 0 and 1 already in indices 0 and 1
	terms = [0,1]
	# set i to the next index to find, currently 2
	i = 2
	# keep going until i reaches the index the user is looking for
	while i <= index:
		# there is no number at the current index
		# but we can add the 2 numbers right before by accessing the the list at indices i-1 and i-2
		terms.append(terms[i-1] + terms[i-2])
		# increment i to keep going
		i = i+1
		
	# now terms contains the fibonacci sequence up until the index provided by the user, which we can print if we want to
	print(terms)
	# we return the element at that index
	return terms[index]
	
	
number = int(input("# in Fibonacci Sequence: "))
print(fibonacci(number))