C# Solution
```\npublic class Solution {\n    public string[] ReorderLogFiles(string[] logs) {\n            SortedList letterLog = new SortedList();\n            List digit
```\npublic class Solution {\n    public string[] ReorderLogFiles(string[] logs) {\n            SortedList<string, string> letterLog = new SortedList<string, string>();\n            List<string> digitLogs = new List<string>(),\n                         result = new List<string>();\n\n            foreach (var item in logs)\n                if (item[item.IndexOf(\' \') + 1] >= \'a\' && item[item.IndexOf(\' \') + 1] <= \'z\')\n                    letterLog.Add(item.Substring(item.IndexOf(\' \') + 1), item);\n                else\n                    digitLogs.Add(item);\n\n            foreach (var item in letterLog)\n                result.Add(item.Value);\n\n            foreach (var item in digitLogs)\n                result.Add(item);\n\n            return result.ToArray();\n    }\n}
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