using System.Collections.Generic;
using Newtonsoft.Json.Serialization;
public string Name { get; set; }
public string Surname { get; set; }
public int Age { get; set; }
public static void Main()
var source = "020406081012141618202224262830323436";
var result = InsertEach(source, Environment.NewLine, 10);
Console.WriteLine(result);
public static string InsertEach(string source, string insertValue, int interval)
var lengthOfNewLine = insertValue.Length;
for (var i = interval; i < source.Length; i += interval + lengthOfNewLine)
source = source.Insert(i, insertValue);