2_even_fibonacci_numbers.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.

Author: Usama Shahid
"""


def even_faibonacci():
    i = 1
    j = 2

    sum = 2
    while i < 4000000 or j < 4000000:
        next = i + j
        i = j
        j = next

        if next % 2 == 0:
            sum += next

    return sum


if __name__ == '__main__':
    print(even_faibonacci())