You [Instruction] Create a code that removes duplicates of an array of strings without using Set data structures in OCaml or Python. The goal is to write a function, which takes in as input a list of words and returns the longest substring between two specific characters. The length of the substring returned by your function should be equal to the number of common letters in both strings. Here's the solution in python code: ```python def findLongestCommonSubstring(str1, str2): def get_common_subsequence(first, second): found = "" for i in range(len(second) - len(first)): if first[i] == second[i]: res.append(first[0]) j=1 else: break return found def findCommonSubstring (str1, str2): common_letters = [] for i in range(len(str1)): if len(common_letters) >= 3 and i < len(str1)-3: if str2[i] == str1[i]: res.append(str1[0]) common_letters.add(str1[i]) j = 1 return "".join(res)