Метод Insert с array

using System;
using System.Collections.Generic;
using System.Linq;

namespace AlgorithmsOverStructureData
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine(); //2 3 4 5 6 7 1
            int[] startNumbers = input.Split(" ").Select(int.Parse).ToArray();
            int number = int.Parse(Console.ReadLine());
            Console.WriteLine("Start array numbers: " + string.Join(", ", startNumbers));
            int [] sortedNumbers = new int[startNumbers.Length + 1];
            for (int index = 0;  index < startNumbers.Length;  index++)
            {
                if(number >= startNumbers[index] && number <= startNumbers[index + 1])
                {
                    sortedNumbers[index] = startNumbers[index];
                    sortedNumbers[index + 1] = number;
                    for(int indexSorted = index + 2; indexSorted < startNumbers.Length + 1; indexSorted++)
                    {
                        sortedNumbers[indexSorted] = startNumbers[index + 1];
                        index++;
                    }
                }

            }

            Console.WriteLine("End array numbers: " + string.Join(", ", sortedNumbers));

            //2 4 5 6
            //3
            //sorted:2 3

        }
    }
}