#! /usr/bin/env python3

def fibonacci(n): 
    if n == 1 or n == 2: 
        return 1
    #Rekursiver Funktionsaufruf 
    #return fibonacci(n - 1) + fibonacci(n - 2)
    fn_1, fn_2 = 1, 1
    for i in range(n-2):
        fn_1, fn_2 = fn_1 + fn_2, fn_1
    return fn_1

def fibonacci_folge(n): 
    if n >= 1:
        #print("yield 1 (fib(1))")
        yield 1
    if n >=2:
        #print("yield 1 (fib(2))")
        yield 1
    #Rekursiver Funktionsaufruf 
    #return fibonacci(n - 1) + fibonacci(n - 2)
    fn_1, fn_2 = 1, 1
    for i in range(n-2):
        fn_1, fn_2 = fn_1 + fn_2, fn_1
        #print("yield {} (fib({}))".format(fn_1, i+3))
        yield fn_1

#print("fib(5) =", fibonacci(5))
#
# print("fib(40) =", fibonacci(400))

for nr, fib in enumerate(fibonacci_folge(30)):
    print(nr+1, fib, sep=' -> ')

#print(list(fibonacci_folge(30)))
#print([i for i in fibonacci_folge(10)])