diff --git a/2024/inputs/.gitkeep b/2024/inputs/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/2024/src/aoc/__main__.py b/2024/src/aoc/__main__.py
index 88467ba..9534731 100644
--- a/2024/src/aoc/__main__.py
+++ b/2024/src/aoc/__main__.py
@@ -1,5 +1,6 @@
 import datetime
 import time
+from typing import IO
 
 import click
 
@@ -19,8 +20,9 @@ from aoc import days
     "-t", "--time", "timing", is_flag=True, help="Print elapsed time afterwards"
 )
 @click.argument("day", required=True)
-def main(day: int, timing: bool, data: str) -> None:
+def main(day: int, timing: bool, data: IO[str]) -> None:
     runner_class = days.get_runner(day)
+    data = data.read()
 
     start = time.perf_counter_ns()
 
diff --git a/2024/src/aoc/days/day1.py b/2024/src/aoc/days/day1.py
index b27f33d..5fcb923 100644
--- a/2024/src/aoc/days/day1.py
+++ b/2024/src/aoc/days/day1.py
@@ -1,13 +1,28 @@
+from collections import defaultdict
+from io import StringIO
 from typing import Any
 
-from . import SeparateRunner
+import numpy
+
+from . import CombinedRunner
 
 
-class DayRunner(SeparateRunner):
+class DayRunner(CombinedRunner):
     @classmethod
-    def part1(cls, _data: str) -> Any:
-        return "Hello"
+    def run_both(cls, data: str) -> tuple[Any, Any]:
+        data = StringIO(data)
+        nums = numpy.loadtxt(data, dtype=numpy.int32)
 
-    @classmethod
-    def part2(cls, _data: str) -> Any:
-        return "world!"
+        left = nums[..., 0]
+        right = nums[..., 1]
+
+        left.sort()
+        right.sort()
+
+        diff = numpy.abs(left - right).sum()
+
+        counts = defaultdict(int)
+        for val in right:
+            counts[val] += 1
+
+        return diff, sum(counts[v] * v for v in left)
diff --git a/2024/tests/samples/01.txt b/2024/tests/samples/01.txt
new file mode 100644
index 0000000..b8af9ad
--- /dev/null
+++ b/2024/tests/samples/01.txt
@@ -0,0 +1,6 @@
+3   4
+4   3
+2   5
+1   3
+3   9
+3   3
diff --git a/2024/tests/test_day1.py b/2024/tests/test_day1.py
new file mode 100644
index 0000000..b6650bb
--- /dev/null
+++ b/2024/tests/test_day1.py
@@ -0,0 +1,14 @@
+import os
+
+from aoc.days.day1 import DayRunner
+
+def get_data() -> str:
+    sample = os.path.dirname(__file__) + "/samples/01.txt"
+    with open(sample, mode="rt", encoding="utf-8") as f:
+        return f.read()
+
+def test_sample_part1():
+    assert DayRunner.part1(get_data()) == 11
+
+def test_sample_part2():
+    assert DayRunner.part2(get_data()) == 31