diff --git a/12/12_2.py b/12/12_2.py
new file mode 100755
index 0000000..67d3aed
--- /dev/null
+++ b/12/12_2.py
@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+
+from collections import namedtuple, UserDict
+
+Pot = namedtuple('Pot', ['id', 'plant'])
+Rule = namedtuple('Rule', ['inp', 'out'])
+newgen = None
+
+class PlantDict(UserDict):
+    def __init__(self, cb, initialdata):
+        super().__init__(initialdata)
+        self._cb = cb
+
+
+    def __missing__(self, key):
+        val = self._cb(key)
+        self[key] = val
+        return val
+
+
+def default_pot(i):
+    return Pot(i, False)
+
+
+def parse_rule(rule):
+    return Rule([c == '#' for c in rule[:5]], '#' in rule.split()[-1])
+    
+
+def print_pots(pots):
+    print(''.join(['#' if pot.plant else '.' for pot in pots]))
+
+
+def main():
+    # I’m aware that I’m overwriting a builtin here
+    input = []
+    with open('input') as f:
+        input = f.readlines()
+    new_gen = PlantDict(default_pot, enumerate([Pot(i, c == '#') for i, c in enumerate(input[0].split(': ')[1])]))
+    print_pots(new_gen.values())
+    rules = [parse_rule(r) for r in input[2:]]
+    before = after = 0
+    for i in range(1000):
+        before = after
+        old_gen = new_gen.copy()
+        ids = new_gen.keys()
+        for i in range(min(ids) - 2, max(ids) + 3): 
+            surroundings = [p.plant for p in [old_gen[x] for x in range(i-2, i+3)]]
+            for rule in rules:
+                if surroundings == rule.inp:
+                    new_gen[i] = Pot(i, rule.out)
+                    break
+        #print_pots(new_gen.values())
+    
+        after = sum([pot.id for pot in new_gen.values() if pot.plant])
+        diff = after - before
+
+    print(diff, before)
+    print(before + diff * (50000000000 - 999))
+
+
+if __name__ == '__main__':
+    main()