diff --git a/README.md b/README.md
index 7ed2186..9fe59b8 100644
--- a/README.md
+++ b/README.md
@@ -30,4 +30,4 @@ Development occurs in language-specific directories:
 |[Day22.hs](hs/src/Day22.hs)|[Day22.kt](kt/src/commonMain/kotlin/com/github/ephemient/aoc2022/Day22.kt)|[day22.py](py/aoc2022/day22.py)|[day22.rs](rs/src/day22.rs)|
 |[Day23.hs](hs/src/Day23.hs)|[Day23.kt](kt/src/commonMain/kotlin/com/github/ephemient/aoc2022/Day23.kt)|[day23.py](py/aoc2022/day23.py)|[day23.rs](rs/src/day23.rs)|
 |[Day24.hs](hs/src/Day24.hs)|[Day24.kt](kt/src/commonMain/kotlin/com/github/ephemient/aoc2022/Day24.kt)|[day24.py](py/aoc2022/day24.py)|[day24.rs](rs/src/day24.rs)|
-|[Day25.hs](hs/src/Day25.hs)|[Day25.kt](kt/src/commonMain/kotlin/com/github/ephemient/aoc2022/Day25.kt)|
+|[Day25.hs](hs/src/Day25.hs)|[Day25.kt](kt/src/commonMain/kotlin/com/github/ephemient/aoc2022/Day25.kt)|[day25.py](py/aoc2022/day25.py)|
diff --git a/py/aoc2022/day25.py b/py/aoc2022/day25.py
new file mode 100644
index 0000000..6d60f8d
--- /dev/null
+++ b/py/aoc2022/day25.py
@@ -0,0 +1,45 @@
+"""
+Day 25: Full of Hot Air
+"""
+
+SAMPLE_INPUT = [
+    "1=-0-2",
+    "12111",
+    "2=0=",
+    "21",
+    "2=01",
+    "111",
+    "20012",
+    "112",
+    "1=-1=",
+    "1-12",
+    "12",
+    "1=",
+    "122",
+]
+
+
+def _unsnafu(snafu):
+    number = 0
+    for char in snafu:
+        number = 5 * number + (-2 if char == "=" else -1 if char == "-" else int(char))
+    return number
+
+
+def _snafu(number):
+    snafu = ""
+    while number:
+        snafu += "012=-"[number % 5]
+        number = (number + 2) // 5
+    return snafu[::-1]
+
+
+def part1(lines):
+    """
+    >>> part1(SAMPLE_INPUT)
+    '2=-1=0'
+    """
+    return _snafu(sum(_unsnafu(line.rstrip()) for line in lines))
+
+
+parts = (part1,)
diff --git a/py/pyproject.toml b/py/pyproject.toml
index 01b3625..ec5b006 100644
--- a/py/pyproject.toml
+++ b/py/pyproject.toml
@@ -56,6 +56,7 @@ day21 = "aoc2022.day21:parts"
 day22 = "aoc2022.day22:parts"
 day23 = "aoc2022.day23:parts"
 day24 = "aoc2022.day24:parts"
+day25 = "aoc2022.day25:parts"
 
 [tool.black]
 target_version = ["py311"]