# Problem_2.py

"""

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

四百万以下的偶数斐波那契数列之和

"""

def fibonacci(x=1, y=1, end=10000):

    if x >= end:

        return []

    else:

        return [x] + fibonacci(y, x+y, end)

fib = fibonacci(end=4000000)

print(fib)

num = sum([i for i in fib if i%2==0])

print(num)