diff --git a/src/maximum_element_after_decreasing_and_rearranging.py b/src/maximum_element_after_decreasing_and_rearranging.py
new file mode 100644
index 0000000..ac52369
--- /dev/null
+++ b/src/maximum_element_after_decreasing_and_rearranging.py
@@ -0,0 +1,15 @@
+class Solution:
+    def maximumElementAfterDecrementingAndRearranging(
+        self, arr: list[int]
+    ) -> int:
+        arr = sorted(arr)
+
+        last = 0
+
+        for x in arr:
+            if x > last + 1:
+                last = last + 1
+            else:
+                last = x
+
+        return last
diff --git a/tests/test_maximum_element_after_decreasing_and_rearranging.py b/tests/test_maximum_element_after_decreasing_and_rearranging.py
new file mode 100644
index 0000000..53d2b92
--- /dev/null
+++ b/tests/test_maximum_element_after_decreasing_and_rearranging.py
@@ -0,0 +1,18 @@
+import pytest
+
+from src.maximum_element_after_decreasing_and_rearranging import Solution
+
+
+@pytest.mark.parametrize(
+    "arr,expected",
+    (
+        ([2, 2, 1, 2, 1], 2),
+        ([100, 1, 1000], 3),
+        ([1, 2, 3, 4, 5], 5),
+    ),
+)
+def test_solution(arr, expected):
+    assert (
+        Solution().maximumElementAfterDecrementingAndRearranging(arr)
+        == expected
+    )