Fibonacci is an algorithm that forms numbers in a pattern to represent growth. The method sums the last two digits to produce the next integer in the sequence. It can be solved both recursively and iterative.

Iterative - Last Digit Fibonacci Number

#Fibonacci Last Digit

def new_fib(n):
    #the_array = []
    last_number = 0
    current_number = 1

    if n <= 1:
        return n

#just store the last digit
    for i in range(n-1):

        fib = last_number + current_number # 0+1 = 1
        last_number = current_number # lastnumber = 1(current = 1)
        current_number = fib % 10
        #the_array.append(fib)
        # add fib = fib + current (fib = 1, current)



    return current_number

n = int(input())
print(new_fib(n))

Iterative - Using an Array to store numbers - This however, will take up a lot of memory on larger numbers. You can remove the array, and it will work the same.

#fibonacci non-recursive

def new_fib(n):
    the_array = []
    last_number = 0
    current_number = 1

    if n <= 1:
        return n


    for i in range(n-1):

        fib = last_number + current_number # 0+1 = 1
        last_number = current_number # lastnumber = 1(current = 1)
        current_number = fib
        the_array.append(fib)
        # add fib = fib + current (fib = 1, current)


    return current_number

n = int(input())
print(new_fib(n))

Recursive

def fib_recur(n):
    if (n <= 1):
        return n

    return fib_recur(n - 1) + fib_recur(n - 2)

n = int(input())
print(fib_recur(n))