import time

def timeit(func):
    '''A simple wrapper to measure execution time'''
    def wrapper(*args, **kwargs):
       timer = time.time()
       rslt = func(*args, **kwargs)
       timer = time.time() - timer
       print(timer)
    return wrapper

def source():
    for k in range(1,100000):
        yield (1+k)*k//2

def make_pairs(src):
    buffer = None
    for chunk in src:
        if buffer:
            yield buffer, chunk
            buffer = None
        else:
            buffer = chunk

def split(src):
    for chunk in src:
        yield chunk
        yield chunk

def multiply(src):
    for x,y in src:
        yield x*y

def gcd(src):
    def helper(x, y):
        if x < y:
            yield from helper(y, x)
        elif y == 0:
            yield x
        else:
            yield from helper(y, x%y)
    for x,y in src:
        yield from helper(x,y)

def combine(src1, src2):
    for x in src1:
        yield x, next(src2)

def divide(src):
    for x,y in src:
        yield x//y

def get_digits(src):
    def helper(x):
        if x != 0:
            yield from helper(x//10)
            yield x%10
    for x in src:
        yield from helper(x)

def sink(src):
    for chunk in src:
        pass

def pipeline():
    s = split(make_pairs(source()))
    sink(get_digits(divide(combine(multiply(s), gcd(s)))))

def repeat():
    for i in range(100):
        pipeline()

timeit(repeat)()