fast short easy java solution. HashMap
\nPLEASE UPVOTE IF YOU LIKE.\n\n        Map map = new HashMap<>();\n\n        for (int i = 0; i < paths.size(); i++){\n            map.put(paths.get(i).get(0), 
```\nPLEASE UPVOTE IF YOU LIKE.\n```\n        Map<String, Integer> map = new HashMap<>();\n\n        for (int i = 0; i < paths.size(); i++){\n            map.put(paths.get(i).get(0), 1);\n        }\n\n        for (int i = 0; i < paths.size(); i++){\n            if (map.get(paths.get(i).get(1)) == null){\n                return paths.get(i).get(1);\n            }\n        }\n        return "";
['Java']