using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Ievadi trapeces abu pamatu garumus");

        int pamats1 = Convert.ToInt32(Console.ReadLine());

        int pamats2 = Convert.ToInt32(Console.ReadLine());

        int x = pamats1+pamats2;

        int atbilde = x/2;

        Console.WriteLine("Vidus līnijas garums ir " + atbilde );

    }

}