Move FileNameGenerator to separate file

Codeforces.Test/FileNameGenerator.cs

@@ -0,0 +1,19 @@
+using System.Collections;
+
+namespace Codeforces.Test;
+
+public class FileNameGenerator : IEnumerable<object[]>
+{
+	private readonly string inputFolder = @"../../../Input";
+	public IEnumerator<object[]> GetEnumerator()
+	{
+		foreach (var input in Directory.GetFiles(inputFolder))
+		{
+			string name = Path.GetFileName(input);
+			string output = $"../../../Output/{name}.a";
+			yield return new object[] { input, output };
+		}
+	}
+
+	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+}