diff --git a/py/aoc/__init__.py b/py/aoc/__init__.py
index 9f19f4b..db133a6 100644
--- a/py/aoc/__init__.py
+++ b/py/aoc/__init__.py
@@ -2,7 +2,11 @@ import sys
 import argparse
 from pathlib import Path
 
-DAYS = {}
+from .y2022 import d04
+
+DAYS = {
+    "2022_04": y2022.d04.solve,
+}
 
 
 def main():
diff --git a/py/aoc/y2022/d04.py b/py/aoc/y2022/d04.py
new file mode 100644
index 0000000..4ff92f5
--- /dev/null
+++ b/py/aoc/y2022/d04.py
@@ -0,0 +1,13 @@
+def solve(inputstr):
+    part1 = 0
+    part2 = 0
+    for line in inputstr.splitlines():
+        elf1, elf2 = line.split(",")
+        s1, e1 = map(int, elf1.split("-"))
+        s2, e2 = map(int, elf2.split("-"))
+        if s1 <= s2 <= e2 <= e1 or s2 <= s1 <= e1 <= e2:
+            part1 += 1
+        if s1 <= e2 and s2 <= e1:
+            part2 += 1
+    print(f"Part 1: {part1}")
+    print(f"Part 2: {part2}")