def fib(x):
    seq = [0]
    fib = 0
    while fib < x:
        if len(seq) == 1:
            seq.append(1)
        else:
            fib = seq[-1] + seq[-2]
            seq.append(fib)
    seq.remove(fib)
    return seq
seq = fib(4000000)
i = 0
while i < len(seq):
    if seq[i] % 2 == 1:
        seq.remove(seq[i])
    else:
        i = i + 1
print sum(seq)