#!/usr/bin/env python

# 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.

MAX=4000000

def main():
    a,b=1,1
    mSum=0

    while (a<MAX):
        if (0==a%2):
            mSum=mSum+a

        b,a=b+a,b

    print mSum

if __name__ == "__main__":
    main()