diff --git a/2024/day1/first-input b/2024/day1/first-input
index 31b4e7a..add1159 100644
--- a/2024/day1/first-input
+++ b/2024/day1/first-input
@@ -997,5 +997,4 @@
 54344   21435
 17846   56504
 61807   42097
-93272   97487
-
+93272   97487
\ No newline at end of file
diff --git a/2024/day1/first.py b/2024/day1/first.py
index 9369e2e..ecf9a8e 100644
--- a/2024/day1/first.py
+++ b/2024/day1/first.py
@@ -1,5 +1,29 @@
-def main():
-    pass
+from pathlib import Path
 
-if __name__ == '__main__':
+
+def get_ordered_lists(data_file: Path) -> tuple[list[int], list[int]]:
+    list1 = list()
+    list2 = list()
+    for line in data_file.open():
+        numbers = line.strip().split("  ")
+        list1.append(int(numbers[0]))
+        list2.append(int(numbers[1]))
+    return sorted(list1), sorted(list2)
+
+
+def compute_distance(list1, list2) -> int:
+    return sum([abs(item2 - item1) for item1, item2 in zip(list1, list2)])
+
+
+def compute(data_file: Path) -> int:
+    list1, list2 = get_ordered_lists(data_file)
+    return compute_distance(list1, list2)
+
+
+def main():
+    file = Path(__file__).parent / "first-input"
+    print(compute(file))
+
+
+if __name__ == "__main__":
     main()
diff --git a/tests/2024/day1/first-data b/tests/2024/day1/first-data
new file mode 100644
index 0000000..dfca0b1
--- /dev/null
+++ b/tests/2024/day1/first-data
@@ -0,0 +1,6 @@
+3   4
+4   3
+2   5
+1   3
+3   9
+3   3
\ No newline at end of file
diff --git a/tests/2024/day1/test_first.py b/tests/2024/day1/test_first.py
new file mode 100644
index 0000000..7f13fd8
--- /dev/null
+++ b/tests/2024/day1/test_first.py
@@ -0,0 +1,14 @@
+from pathlib import Path
+
+from day1 import first
+
+TEST_FILE = Path(__file__).parent / "first-data"
+
+
+def test_first():
+    assert first.compute(TEST_FILE) == 11
+
+
+def test_get_lists():
+    assert first.get_ordered_lists(TEST_FILE)[0] == [1, 2, 3, 3, 3, 4]
+    assert first.get_ordered_lists(TEST_FILE)[1] == [3, 3, 3, 4, 5, 9]