diff --git a/data/example/2025/03.txt b/data/example/2025/03.txt
new file mode 100644
index 000000000..7255fca
--- /dev/null
+++ b/data/example/2025/03.txt
@@ -0,0 +1,4 @@
+987654321111111
+811111111111119
+234234234234278
+818181911112111
diff --git a/src/solution/year_2025/day_03.py b/src/solution/year_2025/day_03.py
new file mode 100644
index 000000000..9081e4d
--- /dev/null
+++ b/src/solution/year_2025/day_03.py
@@ -0,0 +1,64 @@
+from typing import Any
+
+
+def find_max_subnumber(numbers: list[int], length: int) -> int:
+    numbers = list(reversed(numbers))
+    max_search_index = len(numbers)
+    n = 0
+
+    if length > len(numbers):
+        raise ValueError("length greater than numbers length")
+
+    for start_idx in range(length - 1, -1, -1):
+        # local number and loacal max search index
+        ln, lmsi = 0, 0
+        # search from start_idx up to max_search_index
+        for idx in range(start_idx, max_search_index):
+            m = numbers[idx]
+            if idx >= max_search_index:
+                max_search_index = lmsi
+                break
+            # find leftmost highst number and update found digit and local max index
+            if m >= ln:
+                ln = m
+                lmsi = idx
+
+        max_search_index = lmsi
+        n += ln
+        n *= 10
+
+    return n // 10
+
+
+def part_1(input_data: str) -> Any:
+    s = 0
+    for line in input_data.splitlines():
+        parsed = list(map(int, line))
+        s += find_max_subnumber(parsed, 2)
+    return s
+
+
+def part_2(input_data: str) -> Any:
+    s = 0
+    for line in input_data.splitlines():
+        parsed = list(map(int, line))
+        s += find_max_subnumber(parsed, 12)
+    return s
+
+
+def test_find_max_subnumber():
+    assert find_max_subnumber([1, 2, 3, 4, 9], 2) == 49
+    assert find_max_subnumber([1, 2, 3, 4, 5], 2) == 45
+    assert find_max_subnumber([5, 4, 3, 2, 1], 2) == 54
+    assert find_max_subnumber([1, 3, 5, 2, 4], 2) == 54
+    assert find_max_subnumber([8, 1, 8, 2, 7, 3], 3) == 887
+    assert find_max_subnumber([1, 9, 2, 8, 3, 7], 3) == 987
+    assert find_max_subnumber([1, 2, 3, 4, 5], 3) == 345
+
+
+def test_part_1(example_data):
+    assert part_1(example_data) == 357
+
+
+def test_part_2(example_data):
+    assert part_2(example_data) == 3121910778619