using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		var texto  = "13032015joao14032014Juca25";
		List<string> partes = new List<string>(Regex.Split(texto, @"(?<=\G.{12})",
RegexOptions.Multiline));
		
		foreach (var parte in partes){
			Console.WriteLine(parte);
            // 13032015joao
            // 14032014Juca
            // 25
        }
        Console.ReadLine();
	}
}