# 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.

def fibonacci(n):
    """ Vrne n-to Fibonaccijevo število """

    if n <= 1:
        return 1
    else:
        return fibonacci(n-1) + fibonacci(n-2)
    

fib = []
i = 0
while fibonacci(i) < 4000000:
    if fibonacci(i) % 2 == 0:
        fib.append(fibonacci(i))
    i += 1

print(sum(fib))