using System;
using static System.Console;
public class Program {
public static void Main() {
var numero = 123;
Func<string, string> func = numero.ToString;
WriteLine(func("000000"));
Func<string> func2 = numero.ToString;
WriteLine(func2());
Action<string> a = delegate(string txt) { WriteLine(txt); };
Action<string> b = txt => WriteLine(txt);
Action<string> c = WriteLine;
a("abc");
b("abc");
c("abc");
}