# your code goes here
def chunks(s, n):
"""Produce `n`-character chunks from `s`."""
for start in range(0, len(s), n):
yield s[start:start+n]
chars = "ATGAAATAA"
for chunk in chunks(chars, 3):
print chunk
IyB5b3VyIGNvZGUgZ29lcyBoZXJlCmRlZiBjaHVua3Mocywgbik6CiAgICAiIiJQcm9kdWNlIGBuYC1jaGFyYWN0ZXIgY2h1bmtzIGZyb20gYHNgLiIiIgogICAgZm9yIHN0YXJ0IGluIHJhbmdlKDAsIGxlbihzKSwgbik6CiAgICAgICAgeWllbGQgc1tzdGFydDpzdGFydCtuXQoKY2hhcnMgPSAiQVRHQUFBVEFBIgpmb3IgY2h1bmsgaW4gY2h1bmtzKGNoYXJzLCAzKToKICAgIHByaW50IGNodW5r