######################################################################
# 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.
#
#######################################################################

a = 0
b = 1
c = 0
sum = 0

while a + b <= 4000000:
    c = a + b
    a = b
    b = c

    if c % 2 is 0:
        sum += c

print("{}".format(sum))
# Solution: 4613732