using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    #nullable enable

    public static void Main()

    {

        foreach (var combination in GetValues()) {

            foreach (var v in combination) {

                Console.Write(v);

            }

            Console.WriteLine();

        }

    }

    public static IEnumerable<List<string>> GetValues() {

        var fields = new List<string>() {

            "id",

            "name",

            "maconomyjobnum",

            "clientprojectreference"

        };

        for (int i = 0; i < (1 << fields.Count); i++) {

            yield return ConstructBits(i).Select(n => fields[n]).ToList();

        }

    }

    public static IEnumerable<int> ConstructBits(int i) {

        for (int n = 0; i != 0; i /= 2, n++) {

            if ((i & 1) != 0) yield return n;

        }

    }

}