enum_ = (lambda	it,
				zip_ = lambda xs, ys: map(lambda x, y=iter(ys): (x, next(y)), xs),
				count_ = iter(
						lambda x=[-1]: x.__setitem__(-1, x[-1] + 1) or x[-1],
						None
						)
				: zip_(count_, it)
		)

print(*enum_(range(2, 20, 2)))