using System;
public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] pass = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string e = Console.ReadLine() ?? string.Empty;

        int num = int.Parse(Console.ReadLine() ?? string.Empty);
        string[] number = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        int yuki = int.Parse(Console.ReadLine() ?? string.Empty);

        int count = 0;
        for (int i = 0; i < number.Length; i++)
        {
            count += int.Parse(number[i]);
        }
        Console.WriteLine(count-yuki);

    }
}