diff --git a/README.md b/README.md
index ccd54387..61f4eb99 100644
--- a/README.md
+++ b/README.md
@@ -452,3 +452,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2529. Maximum Count of Positive Integer and Negative Integer       | [Link](https://leetcode.com/problems/maximum-count-of-positive-integer-and-negative-integer/)       | [Link](./lib/easy/2529_maximum_count_of_positive_integer_and_negative_integer.rb)       |
 | 2535. Difference Between Element Sum and Digit Sum of an Array     | [Link](https://leetcode.com/problems/difference-between-element-sum-and-digit-sum-of-an-array/)     | [Link](./lib/easy/2535_difference_between_element_sum_and_digit_sum_of_an_array.rb)     |
 | 2540. Minimum Common Value                                         | [Link](https://leetcode.com/problems/minimum-common-value/)                                         | [Link](./lib/easy/2540_minimum_common_value.rb)                                         |
+| 2544. Alternating Digit Sum                                        | [Link](https://leetcode.com/problems/alternating-digit-sum/)                                        | [Link](./lib/easy/2544_alternating_digit_sum.rb)                                        |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 43cb7459..6741ae31 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 = '5.9.1'
+  s.version = '5.9.2'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'
diff --git a/lib/easy/2544_alternating_digit_sum.rb b/lib/easy/2544_alternating_digit_sum.rb
new file mode 100644
index 00000000..25a9a091
--- /dev/null
+++ b/lib/easy/2544_alternating_digit_sum.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/alternating-digit-sum/
+# @param {Integer} n
+# @return {Integer}
+def alternate_digit_sum(n)
+  result = 0
+  factor = 1
+  n.to_s.each_char do |c|
+    result += c.to_i * factor
+    factor *= -1
+  end
+
+  result
+end
diff --git a/test/easy/test_2544_alternating_digit_sum.rb b/test/easy/test_2544_alternating_digit_sum.rb
new file mode 100644
index 00000000..9547d3e0
--- /dev/null
+++ b/test/easy/test_2544_alternating_digit_sum.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/easy/2544_alternating_digit_sum'
+require 'minitest/autorun'
+
+class AlternatingDigitSumTest < ::Minitest::Test
+  def test_default
+    assert_equal(4, alternate_digit_sum(521))
+    assert_equal(1, alternate_digit_sum(111))
+    assert_equal(0, alternate_digit_sum(886_996))
+  end
+end