Pure maths || easy || beats 100%
Code\n\nclass Solution {\npublic:\n    long mod = 1e9 + 7;\n    long pow(int x, int y){\n        long ans = 1;\n        long z = x%mod;\n        while(y){\n    
# Code\n```\nclass Solution {\npublic:\n    long mod = 1e9 + 7;\n    long pow(int x, int y){\n        long ans = 1;\n        long z = x%mod;\n        while(y){\n            if(y & 1) ans = (ans*z)%mod;\n            z = (z * z) % mod;\n            y >>= 1;\n        }\n        return ans;\n    }\n    int stringCount(int n) {\n        int k = 26;\n        long ans = ((pow(k, n) - (n+75)*pow(k-1, n-1) + (2*n + 72)*pow(k-2, n-1) - (n+k-3)*pow(k-3,n-1))%mod+mod)%mod;\n        return ans;\n    }\n};\n```
['C++']