#!/usr/bin/python
"""
"""
data = [1, 2]
def generate_fib():
    index = 2
    while True:
        data.append(data[index - 1] + data[index - 2])
        if data[index] >= 4000000:
            return data
        index += 1
generate_fib()
sum = 0
for i in data:
    if i % 2 == 0:
        sum += i
print sum