diff --git a/src/my_project/interviews/amazon_high_frequency_23/round_2/valid_palindrome_round_1.py b/src/my_project/interviews/amazon_high_frequency_23/round_2/valid_palindrome_round_1.py
new file mode 100644
index 00000000..c885a129
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/round_2/valid_palindrome_round_1.py
@@ -0,0 +1,24 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+import re
+
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+
+        # to lowercase
+        s = s.lower()
+
+        # Remove non-alphanumerical characters
+        s = re.sub(pattern='[^a-zA-Z0-9]', repl='', string=s)
+
+
+        # Identify palindrome
+
+        len_s = len(s)
+
+        for i in range(len_s//2):
+
+            if s[i] != s[len_s - 1 - i]:
+                return False 
+            
+        return True 
\ No newline at end of file
diff --git a/src/my_project/interviews/top_150_questions_round_21/roman_to_integer.py b/src/my_project/interviews/top_150_questions_round_21/roman_to_integer.py
new file mode 100644
index 00000000..2ce7ca52
--- /dev/null
+++ b/src/my_project/interviews/top_150_questions_round_21/roman_to_integer.py
@@ -0,0 +1,21 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def romanToInt(self, s: str) -> int:
+
+        roman_to_dict = {'I':1,'V':5,'X':10,'L':50,'C':100,'D':500,'M':1000}
+
+        len_s = len(s)
+
+        answer = roman_to_dict[s[len_s - 1]]
+
+        for i in range(len_s - 1):
+            
+            if roman_to_dict[s[len_s - 2 - i]] \
+                                    < roman_to_dict[s[len_s - 1 - i]]:
+                answer -= roman_to_dict[s[len_s - 2 - i]]
+            else: 
+                answer += roman_to_dict[s[len_s - 2 - i]]
+
+        return answer
\ No newline at end of file
diff --git a/tests/test_150_questions_round_21/test_roman_to_integer_round_21.py b/tests/test_150_questions_round_21/test_roman_to_integer_round_21.py
new file mode 100644
index 00000000..fb903a8a
--- /dev/null
+++ b/tests/test_150_questions_round_21/test_roman_to_integer_round_21.py
@@ -0,0 +1,17 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_21\
+.roman_to_integer import Solution
+
+class RomanToIntegerTestCase(unittest.TestCase):
+
+    def test_patter_one(self):
+        solution = Solution()
+        output = solution.romanToInt(s='VII')
+        target = 7
+        self.assertEqual(output, target)
+
+    def test_patter_two(self):
+        solution = Solution()
+        output = solution.romanToInt(s='IX')
+        target = 9
+        self.assertEqual(output, target)
\ No newline at end of file