using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var letters = new [] {'a', 'b', 'c', 'd'};

        var digits = new [] {1, 2, 3};

        var results = letters

            .Join(digits, l => 1, d => 1, (l, d) => new {Letter = l, Digit = d});

        foreach (var r in results) {

            Console.WriteLine(r.Letter + " " + r.Digit);

        }

    }

}