diff --git a/README.md b/README.md
index 775d705e..459145ff 100644
--- a/README.md
+++ b/README.md
@@ -665,6 +665,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1110. Delete Nodes And Return Forest                             | [Link](https://leetcode.com/problems/delete-nodes-and-return-forest/)                              | [Link](./lib/medium/1110_delete_nodes_and_return_forest.rb)                             | [Link](./test/medium/test_1110_delete_nodes_and_return_forest.rb)                             |
 | 1111. Maximum Nesting Depth of Two Valid Parentheses Strings     | [Link](https://leetcode.com/problems/maximum-nesting-depth-of-two-valid-parentheses-strings/)      | [Link](./lib/medium/1111_maximum_nesting_depth_of_two_valid_parentheses_strings.rb)     | [Link](./test/medium/test_1111_maximum_nesting_depth_of_two_valid_parentheses_strings.rb)     |
 | 1123. Lowest Common Ancestor of Deepest Leaves                   | [Link](https://leetcode.com/problems/lowest-common-ancestor-of-deepest-leaves/)                    | [Link](./lib/medium/1123_lowest_common_ancestor_of_deepest_leaves.rb)                   | [Link](./test/medium/test_1123_lowest_common_ancestor_of_deepest_leaves.rb)                   |
+| 1161. Maximum Level Sum of a Binary Tree                         | [Link](https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree/)                          | [Link](./lib/medium/1161_maximum_level_sum_of_a_binary_tree.rb)                         | [Link](./test/medium/test_1161_maximum_level_sum_of_a_binary_tree.rb)                         |
 | 1400. Construct K Palindrome Strings                             | [Link](https://leetcode.com/problems/construct-k-palindrome-strings/)                              | [Link](./lib/medium/1400_construct_k_palindrome_strings.rb)                             | [Link](./test/medium/test_1400_construct_k_palindrome_strings.rb)                             |
 | 2116. Check if a Parentheses String Can Be Valid                 | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/)                  | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb)                 | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb)                 |
 | 2425. Bitwise XOR of All Pairings                                | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/)                                 | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb)                                | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb)                                |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index af063668..a561b987 100644
--- a/leetcode-ruby.gemspec
+++ b/leetcode-ruby.gemspec
@@ -5,7 +5,7 @@ require 'English'
 ::Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
   s.name = 'leetcode-ruby'
-  s.version = '8.3.2'
+  s.version = '8.3.3'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/1161_maximum_level_sum_of_a_binary_tree.rb b/lib/medium/1161_maximum_level_sum_of_a_binary_tree.rb
new file mode 100644
index 00000000..05f608a1
--- /dev/null
+++ b/lib/medium/1161_maximum_level_sum_of_a_binary_tree.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree/
+# @param {TreeNode} root
+# @return {Integer}
+def max_level_sum(root)
+  nodes = [root]
+  max = -::Float::INFINITY
+  max_level = 1
+  level = 1
+
+  until nodes.empty?
+    size = nodes.size
+    sum = 0
+
+    size.times do
+      node = nodes.shift
+      sum += node.val
+
+      nodes << node.left if node.left
+      nodes << node.right if node.right
+    end
+
+    if sum > max
+      max = sum
+      max_level = level
+    end
+
+    level += 1
+  end
+
+  max_level
+end
diff --git a/test/medium/test_1161_maximum_level_sum_of_a_binary_tree.rb b/test/medium/test_1161_maximum_level_sum_of_a_binary_tree.rb
new file mode 100644
index 00000000..e7d9267a
--- /dev/null
+++ b/test/medium/test_1161_maximum_level_sum_of_a_binary_tree.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/1161_maximum_level_sum_of_a_binary_tree'
+require 'minitest/autorun'
+
+class MaximumLevelSumOfABinaryTreeTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      2,
+      max_level_sum(
+        ::TreeNode.build_tree(
+          [1, 7, 0, 7, -8, nil, nil]
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      2,
+      max_level_sum(
+        ::TreeNode.build_tree(
+          [989, nil, 10_250, 98_693, -89_388, nil, nil, nil, -32_127]
+        )
+      )
+    )
+  end
+end