using System;

public class Program

{

    public static void Main()

    {

        A.a("", "");

    }

}

​

static class A

{

    public static void a(string x, params string[] y)

    {

        Console.WriteLine("a1");

    }

    public static void a(string x, string y, params string[] z)

    {

        Console.WriteLine("a2");

    }

}