""" 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. """

x1 = 1
x2 = 2
count = 2
while x2 < 4000000:
    x2_new = x1 + x2
    x1 = x2
    x2 = x2_new
    if x2 % 2 == 0:
        count += x2
print(count)