diff --git a/day12.py b/day12.py
new file mode 100644
index 0000000..d418af9
--- /dev/null
+++ b/day12.py
@@ -0,0 +1,54 @@
+from tools.aoc import AOCDay
+from typing import Any, Dict, List
+
+
+def getCaveMap(lines: List[List[str]]) -> Dict[str, List[str]]:
+    m = {}
+    for l in lines:
+        if l[0] in m:
+            m[l[0]].append(l[1])
+        else:
+            m[l[0]] = [l[1]]
+
+        if l[1] in m:
+            m[l[1]].append(l[0])
+        else:
+            m[l[1]] = [l[0]]
+
+    return m
+
+
+def getPaths(caveMap: Dict[str, List[str]], start: str, visited: List[str], noDouble: bool = True) -> List[List[str]]:
+    paths = []
+    visited.append(start)
+    for thisCave in caveMap[start]:
+        if thisCave == 'start':
+            continue
+
+        if thisCave == 'end':
+            paths.append(['end'])
+            continue
+
+        foundDouble = False
+        if thisCave.islower() and thisCave in visited:
+            if noDouble:
+                continue
+            foundDouble = True
+
+        sub_paths = getPaths(caveMap, thisCave, visited.copy(), noDouble or foundDouble)
+        [paths.append(x) for x in sub_paths if 'end' in x]
+
+    return paths
+
+
+class Day(AOCDay):
+    test_solutions_p1 = [10, 19, 226, 5076]
+    test_solutions_p2 = [36, 103, 3509, 145643]
+
+    def part1(self) -> Any:
+        caveMap = getCaveMap(self.getInputAsArraySplit("-"))
+        return len(getPaths(caveMap, 'start', []))
+
+    def part2(self) -> Any:
+        caveMap = getCaveMap(self.getInputAsArraySplit("-"))
+        return len(getPaths(caveMap, 'start', [], False))
diff --git a/inputs/input12 b/inputs/input12
new file mode 100644
index 0000000..1296eb6
--- /dev/null
+++ b/inputs/input12
@@ -0,0 +1,22 @@
+end-MY
+MY-xc
+ho-NF
+start-ho
+NF-xc
+NF-yf
+end-yf
+xc-TP
+MY-qo
+yf-TP
+dc-NF
+dc-xc
+start-dc
+yf-MY
+MY-ho
+EM-uh
+xc-yf
+ho-dc
+uh-NF
+yf-ho
+end-uh
+start-NF
diff --git a/inputs/test_input12_1_0 b/inputs/test_input12_1_0
new file mode 100644
index 0000000..6fd8c41
--- /dev/null
+++ b/inputs/test_input12_1_0
@@ -0,0 +1,7 @@
+start-A
+start-b
+A-c
+A-b
+b-d
+A-end
+b-end
diff --git a/inputs/test_input12_1_1 b/inputs/test_input12_1_1
new file mode 100644
index 0000000..62cc714
--- /dev/null
+++ b/inputs/test_input12_1_1
@@ -0,0 +1,10 @@
+dc-end
+HN-start
+start-kj
+dc-start
+dc-HN
+LN-dc
+HN-end
+kj-sa
+kj-HN
+kj-dc
diff --git a/inputs/test_input12_1_2 b/inputs/test_input12_1_2
new file mode 100644
index 0000000..65f3833
--- /dev/null
+++ b/inputs/test_input12_1_2
@@ -0,0 +1,18 @@
+fs-end
+he-DX
+fs-he
+start-DX
+pj-DX
+end-zg
+zg-sl
+zg-pj
+pj-he
+RW-he
+fs-DX
+pj-RW
+zg-RW
+start-pj
+he-WI
+zg-he
+pj-fs
+start-RW
diff --git a/inputs/test_input12_1_3 b/inputs/test_input12_1_3
new file mode 100644
index 0000000..1296eb6
--- /dev/null
+++ b/inputs/test_input12_1_3
@@ -0,0 +1,22 @@
+end-MY
+MY-xc
+ho-NF
+start-ho
+NF-xc
+NF-yf
+end-yf
+xc-TP
+MY-qo
+yf-TP
+dc-NF
+dc-xc
+start-dc
+yf-MY
+MY-ho
+EM-uh
+xc-yf
+ho-dc
+uh-NF
+yf-ho
+end-uh
+start-NF
diff --git a/inputs/test_input12_2_0 b/inputs/test_input12_2_0
new file mode 100644
index 0000000..6fd8c41
--- /dev/null
+++ b/inputs/test_input12_2_0
@@ -0,0 +1,7 @@
+start-A
+start-b
+A-c
+A-b
+b-d
+A-end
+b-end
diff --git a/inputs/test_input12_2_1 b/inputs/test_input12_2_1
new file mode 100644
index 0000000..62cc714
--- /dev/null
+++ b/inputs/test_input12_2_1
@@ -0,0 +1,10 @@
+dc-end
+HN-start
+start-kj
+dc-start
+dc-HN
+LN-dc
+HN-end
+kj-sa
+kj-HN
+kj-dc
diff --git a/inputs/test_input12_2_2 b/inputs/test_input12_2_2
new file mode 100644
index 0000000..65f3833
--- /dev/null
+++ b/inputs/test_input12_2_2
@@ -0,0 +1,18 @@
+fs-end
+he-DX
+fs-he
+start-DX
+pj-DX
+end-zg
+zg-sl
+zg-pj
+pj-he
+RW-he
+fs-DX
+pj-RW
+zg-RW
+start-pj
+he-WI
+zg-he
+pj-fs
+start-RW
diff --git a/inputs/test_input12_2_3 b/inputs/test_input12_2_3
new file mode 100644
index 0000000..1296eb6
--- /dev/null
+++ b/inputs/test_input12_2_3
@@ -0,0 +1,22 @@
+end-MY
+MY-xc
+ho-NF
+start-ho
+NF-xc
+NF-yf
+end-yf
+xc-TP
+MY-qo
+yf-TP
+dc-NF
+dc-xc
+start-dc
+yf-MY
+MY-ho
+EM-uh
+xc-yf
+ho-dc
+uh-NF
+yf-ho
+end-uh
+start-NF