using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var numbers = new[] { 1, 2, 3, 4, 5 };

​

        var pairs = numbers.Zip(numbers.Skip(1));

​

        foreach (var pair in pairs)

        {

            Console.WriteLine($"First: {pair.First}, Second: {pair.Second}");

        }

    }

}