Python3 easy solution
\nclass Solution:\n\tdef longestWord(self, words: List[str]) -> str:\n\t\twords.sort()\n\t\tht = {}\n\t\tfor w in words:\n\t\t\tif len(w) == 1 and w not in ht:\
```\nclass Solution:\n\tdef longestWord(self, words: List[str]) -> str:\n\t\twords.sort()\n\t\tht = {}\n\t\tfor w in words:\n\t\t\tif len(w) == 1 and w not in ht:\n\t\t\t\tht[w] = 1\n\t\t\t\tcontinue\n\t\t\tif w[:-1] in ht:\n\t\t\t\tht[w] = 1\n\t\ts = sorted(ht.keys(),reverse=True,key=len)\n\t\t#print(s)\n\t\tres = []\n\t\tfor item in s:\n\t\t\tif len(res) == 0:\n\t\t\t\tres.append(item)\n\t\t\t\tcontinue\n\t\t\tif len(item) < len(res[0]):\n\t\t\t\tbreak\n\t\t\telse:\n\t\t\t\tres.append(item)\n\t\tif len(res) == 0:\n\t\t\treturn ""\n\t\treturn res[0]\n\n```
['Python3']