diff --git a/README.md b/README.md
index 30ddf934..0753db13 100644
--- a/README.md
+++ b/README.md
@@ -707,6 +707,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1557. Minimum Number of Vertices to Reach All Nodes                                 | [Link](https://leetcode.com/problems/minimum-number-of-vertices-to-reach-all-nodes/)                                 | [Link](./lib/medium/1557_minimum_number_of_vertices_to_reach_all_nodes.rb)                                 | [Link](./test/medium/test_1557_minimum_number_of_vertices_to_reach_all_nodes.rb)                                 |
 | 1609. Even Odd Tree                                                                 | [Link](https://leetcode.com/problems/even-odd-tree/)                                                                 | [Link](./lib/medium/1609_even_odd_tree.rb)                                                                 | [Link](./test/medium/test_1609_even_odd_tree.rb)                                                                 |
 | 1630. Arithmetic Subarrays                                                          | [Link](https://leetcode.com/problems/arithmetic-subarrays/)                                                          | [Link](./lib/medium/1630_arithmetic_subarrays.rb)                                                          | [Link](./test/medium/test_1630_arithmetic_subarrays.rb)                                                          |
+| 1641. Count Sorted Vowel Strings                                                    | [Link](https://leetcode.com/problems/count-sorted-vowel-strings/)                                                    | [Link](./lib/medium/1641_count_sorted_vowel_strings.rb)                                                    | [Link](./test/medium/test_1641_count_sorted_vowel_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)                                                   |
 | 2429. Minimize XOR                                                                  | [Link](https://leetcode.com/problems/minimize-xor/)                                                                  | [Link](./lib/medium/2429_minimize_xor.rb)                                                                  | [Link](./test/medium/test_2429_minimize_xor.rb)                                                                  |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index b3af6069..dcdaddce 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 = '8.7.3'
+  s.version = '8.7.4'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/1641_count_sorted_vowel_strings.rb b/lib/medium/1641_count_sorted_vowel_strings.rb
new file mode 100644
index 00000000..041169e1
--- /dev/null
+++ b/lib/medium/1641_count_sorted_vowel_strings.rb
@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/count-sorted-vowel-strings/
+# @param {Integer} n
+# @return {Integer}
+def count_vowel_strings(n)
+  (n + 4) * (n + 3) * (n + 2) * (n + 1) / 24
+end
diff --git a/test/medium/test_1641_count_sorted_vowel_strings.rb b/test/medium/test_1641_count_sorted_vowel_strings.rb
new file mode 100644
index 00000000..74aae3f6
--- /dev/null
+++ b/test/medium/test_1641_count_sorted_vowel_strings.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/1641_count_sorted_vowel_strings'
+require 'minitest/autorun'
+
+class CountSortedVowelStringsTest < ::Minitest::Test
+  def test_default_one = assert_equal(5, count_vowel_strings(1))
+
+  def test_default_two = assert_equal(15, count_vowel_strings(2))
+
+  def test_default_three = assert_equal(66_045, count_vowel_strings(33))
+end