Given a series of game results such as `xxxx beats yyyy`, output the final ranking.\n\n**Example 1:**\n```\nInput: ["a beats b", "b beats c", "c beats d"]\nOutput: ["a", "b", "c", "d"]\n```\n\n**Example 2:**\n```\nInput: ["a beats b", "a beats c"]\nOutput: ["a", "b", "c"] or ["a", "c", "b"]\n```\n\nYou can assume that there are no cycles.

Given a series of game results such as xxxx beats yyyy, output the final ranking.\n\nExample 1:\n\nInput: ["a beats b", "b beats c", "c beats d"]\nOutput: ["a",