using System;

public class Program

{

    public static void Main()

    {

        var date1 = new DateTime(2014, 10, 11);

        var date2 = new DateTime(2016, 12, 21);

        Console.WriteLine(GetDuration(date1, date2));

    }

    public static string GetDuration(DateTime date1, DateTime date2) 

    {       

        var period = date2.AddDays(1) - date1;

        var date = new DateTime(period.Ticks);

        var totalYears = date.Year - 1;

        var totalMonths = ((date.Year - 1) * 12) + date.Month - 1;

        var extraMonths = totalMonths - (totalYears * 12);

        return string.Format("{0} years {1} months", totalYears, extraMonths);

    }

}