Python | Video Walkthrough | Statistics for Dummies
Click Here For Video Walkthrough\n\nclass Solution:\n    def stringCount(self, n: int) -> int:\n        l_0 = 25 ** n\n        e_0 = 25 ** n\n        t_0 = 25 *
[Click Here For Video Walkthrough](https://youtu.be/9E09QrzMjgo)\n```\nclass Solution:\n    def stringCount(self, n: int) -> int:\n        l_0 = 25 ** n\n        e_0 = 25 ** n\n        t_0 = 25 ** n\n        e_1 = n * 25 ** (n-1)\n        e_2 = e_0 + e_1\n        \n        l_0_t_0 = 24 ** n\n        \n        l_0_e_2 = 24 ** n + n * 24 ** (n-1)\n        t_0_e_2 = 24 ** n + n * 24 ** (n-1)\n        l_0_t_0_e_2 = 23 ** n + n * 23 ** (n-1)\n        \n        \n        return (26 ** n - (l_0 + e_2 + t_0 - l_0_t_0 - l_0_e_2 - t_0_e_2 + l_0_t_0_e_2)) % (10 ** 9 + 7)\n```
['Python']