using System;
using System.IO;
 
public class Test {
	private static string GetPathWithoutExtensions(string path) {
		var directoryPath = Path.GetDirectoryName(path);
		var baseName = Path.GetFileName(path);
		var baseNameWithoutExtensions = baseName.Split(new[] {'.'}, 2)[0];
 
		return Path.Combine(directoryPath, baseNameWithoutExtensions);
	}
 
	public static void Main() {
		Console.WriteLine(
			GetPathWithoutExtensions(
				@"C:\Users\me\Desktop\filename.This.Is.An.Extension"));
	}
}

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