using System;
using System.Linq;

public class Test
{
	public static void Main()
	{
		var freq = 0;
            for(var first = 100; first <= 999; ++first)
            {
                var firstSum = first.ToString().Select(x => Convert.ToInt32(x - '0')).ToArray<int>().Sum();
                for(var second = 000; second <= 999; ++second)
                {
                    var secondSum = second.ToString().Select(x => Convert.ToInt32(x - '0')).ToArray<int>().Sum();
                    if (firstSum == secondSum) ++freq;
                    
                }
            }
            Console.WriteLine(freq);    
	}
}