import requests
import re
import json

r = requests.get(url, headers=HEADERS, allow_redirects=True)
m = re.search(r"window\.\_cianConfig\['offer-card'\] = (\[.+\]);", r.text)
if not m: raise Exception("Invalid answer: " + r.text)
data = json.loads(m.group(1))
defaultState = [r["value"] for r in data if r["key"] == "defaultState"][0]
fullPhotoUrls = [p["thumbnailUrl"] for p in defaultState["offerData"]["offer"]["photos"]]