ででででできたお！！
みんな㌧ｸｽ！！

string input = Console.ReadLine();
StringBuilder sb = new StringBuilder();
sb.Append("using System;");
sb.Append("namespace Temp");
sb.Append("{");
sb.Append("public class TempClass");
sb.Append("{");
sb.Append("public object TempMethod()");
sb.Append("{");
sb.Append("return " + input + ";");
sb.Append("}");
sb.Append("}");
sb.Append("}");
Microsoft.CSharp.CSharpCodeProvider provider = new Microsoft.CSharp.CSharpCodeProvider();
CompilerParameters parameters = new CompilerParameters();
parameters.GenerateExecutable = false;
parameters.GenerateInMemory = true;
parameters.TreatWarningsAsErrors = false;
CompilerResults result = provider.CompileAssemblyFromSource(parameters, sb.ToString());
if (result.Errors.Count == 0)
{
Assembly assembly = result.CompiledAssembly;
Type type = assembly.GetType("Temp.TempClass");
Object obj = Activator.CreateInstance(type);
MethodInfo methodInfo = type.GetMethod("TempMethod");
Console.WriteLine(methodInfo.Invoke(obj, null));
}

1+1って入力したら2ってちゃんと帰ってきたぞｗｗｗｗｗ