using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var input = @"199

200

208

210

200

207

240

269

260

263";

​

        var numbers = input.Split(Environment.NewLine).Select(x => int.Parse(x)).ToArray();

        var count = 0;

        for(int pos = 0; pos < numbers.Length; pos++)

        {

            if (pos >= 3)

            {

                var currentTotal = numbers[pos] + numbers[pos - 1] + numbers[pos - 2];

                var previousTotal = numbers[pos - 1] + numbers[pos - 2] + numbers[pos - 3];

​

                if(currentTotal > previousTotal)

                {

                    count++;

                }

            }

        }

        Console.WriteLine(count);

    }

}