using System;
using Microsoft.CSharp;
using System.Collections.Generic;
using System.CodeDom.Compiler;
using System.Diagnostics;
 
class Program
{
    static void Main(string[] args)
    {
        string sourceCode = "class e{static void Main(){System.Console.Write(new char[1\n#if l\n#else\n*5]{'w','o','r','l','d'\n#if o\n#else\n});\n#endif\n}\n#endif\n}";
 
        Console.WriteLine(isPristine(sourceCode) ? "Pristine" : "Not pristine");
        Console.ReadLine();
    }
 
    static bool isPristine(string sourceCode)
    {
        using (var csc = new CSharpCodeProvider(new Dictionary<string, string>() { { "CompilerVersion", "v3.5" } }))
        {
            var parameters = new CompilerParameters(new[] { "mscorlib.dll", "System.Core.dll" });
 
            int length = sourceCode.Length;
            List<string> substringsThatWork = new List<string>();
 
            for (int i = 0; i < length; i++)
            {
                for (int j = 1; j < length - i; j++)
                {
                    string sourceWithRemoval = sourceCode.Remove(i, j);
                    CompilerResults results = csc.CompileAssemblyFromSource(parameters, sourceWithRemoval);
 
                    if (results.Errors.Count == 0)
                    {
                        Debug.WriteLine("Still works by removing:");
                        Debug.WriteLine("@{0}@ ", sourceWithRemoval);
                        Debug.WriteLine("At index {0}.", i);
 
                        return false;
                    }
                }
            }
        }
 
        return true;
    }
}

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