using System;
using System.Collections.Generic;
using System.Linq;

public class Test
{
	public static void Main()
	{
		var n = Console.ReadLine();
		var alist = Console.ReadLine()
					.Split(' ')
					.Select(x => int.Parse(x))
					.ToList();
		var v = int.Parse(Console.ReadLine());
		Console.WriteLine(alist.Sum() - v);
	}
}