diff --git a/day12/common.py b/day12/common.py
index 3acc00a..bd15537 100644
--- a/day12/common.py
+++ b/day12/common.py
@@ -1,7 +1,7 @@
 from dataclasses import dataclass
 from typing import NamedTuple, NewType
 import re
-
+import logging
 
 def im_replace(line: str, mask: str) -> str:
     idx = 0
@@ -21,31 +21,27 @@ class SpringLine(NamedTuple):
 
     def arrangments(self) -> list[str]:
         count_im = self.line.count("?")
-        print(count_im)
+        logging.debug(count_im)
         possibles = []
         for i in range(pow(2, count_im)):
+            debug_str = ""
             rep_str = f"{i:b}".rjust(count_im, "0").replace("0", ".").replace("1", "#")
-            print(rep_str, end=" / ")
+            debug_str += rep_str + " / "
             tentative = im_replace(self.line, rep_str)
             possible = SpringLine(tentative, self.groups)
-            print(possible, end=": ")
+            debug_str += str(possible)+": "
             if possible.is_valid():
                 possibles.append(im_replace(self.line, rep_str))
-                print("valid")
+                debug_str += "valid"
             else:
-                print("invalid")
+                debug_str += "invalid"
+            logging.debug(debug_str)
         return possibles
 
     def is_valid(self) -> bool:
-        # TODO: correct this (re.match with generated pattern based en groups)
-        line_copy = self.line
-
-        for group in self.groups:
-            idx = line_copy.find("#" * group)
-            if idx == -1:
-                return False
-            line_copy = line_copy[idx + group :]
-        return True
+        pattern = "^\.*" + "\.+".join(["#" * i for i in self.groups]) + "\.*$"
+        # logging.debug(pattern)
+        return re.match(pattern, self.line)
 
 
 Spring = NewType("Spring", list[SpringLine])
@@ -56,7 +52,7 @@ def parse(input_file: str) -> Spring:
     with open(input_file, "r", encoding="utf-8") as inputfd:
         while line := inputfd.readline():
             if match := re.match("([?#.]+)\s([0-9,]+)", line):
-                # print(match.group(0))
+                # logging.debug(match.group(0))
                 spring_lines.append(
                     SpringLine(
                         match.group(1),
diff --git a/day12/part1.py b/day12/part1.py
index 52cd0c3..2ef65d4 100755
--- a/day12/part1.py
+++ b/day12/part1.py
@@ -5,9 +5,9 @@ from common import *
 
 def part1(input_file: str) -> int:
     spring = parse(input_file)
-    print(spring)
-    interm = list(map(lambda s: s.arrangments(), spring))
-    print(interm)
-    interm = list(map(len, interm))
-    print(interm)
-    return sum(interm)
+    #interm = list(map(lambda s: s.arrangments(), spring))
+    #interm = list(map(len, interm))
+    return sum(list(map(len, map(lambda s: s.arrangments(), spring))))
+
+if __name__=="__main__":
+    print(part1("input.txt"))
\ No newline at end of file
diff --git a/day12/part2.py b/day12/part2.py
index 4367f5b..c98728b 100755
--- a/day12/part2.py
+++ b/day12/part2.py
@@ -1,3 +1,7 @@
 #!/usr/bin/env python3.11
 
 from common import *
+
+
+def part2(input_file:str) -> int:
+    return 0
\ No newline at end of file
diff --git a/day12/test.py b/day12/test.py
index 9e1d082..43ffd6a 100755
--- a/day12/test.py
+++ b/day12/test.py
@@ -23,7 +23,7 @@ class DayXTests(TestCase):
         self.assertEqual(part1("example_input.txt"), 21)
 
     def test_part2(self):
-        pass
+        self.assertEqual(part2("example_input.txt"), 525152)
 
 
 if __name__ == "__main__":