def euler_25():
"""What is the first term in the Fibonacci sequence to contain 1000 digits?"""
from itertools import takewhile
from eutil import fib, ilen
return ilen(takewhile(lambda x: len(str(x)) < 1000, fib()))
def euler_2():
"""By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms."""
from itertools import takewhile
from eutil import fib
return sum(filter(lambda x: x % 2 == 0, takewhile(lambda y: y < 4000000, fib())))