Python solution faster than 100 percent!
\nclass Solution:\n    def modifyString(self, s: str) -> str:\n        ans=\'\'\n        if len(s)==1:\n            if s[0]==\'?\':\n                return \'a\
```\nclass Solution:\n    def modifyString(self, s: str) -> str:\n        ans=\'\'\n        if len(s)==1:\n            if s[0]==\'?\':\n                return \'a\'\n            else:\n                return s\n            \n        if s[0]=="?":\n            for j in range(97,124):\n                if ord(s[1])!=j:\n                    ans+=chr(j)\n                    break\n        else:\n            ans+=s[0]\n        for i in range(1,len(s)):\n            if s[i]=="?":\n                if i==len(s)-1:\n                    for j in range(97,124):\n                        if ord(ans[i-1])!=j:\n                            ans+=chr(j)\n                            break\n                else:\n                    for j in range(97,124):\n                        if ord(ans[i-1])!=j and ord(s[i+1])!=j:\n                            ans+=chr(j)\n                            break\n            else:\n                ans+=s[i]\n        return ans\n```
['Python', 'Python3']