using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class Magatro
{
    static void Main()
    {
        Console.ReadLine();
        int[] A = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
        int v = int.Parse(Console.ReadLine());
        Console.WriteLine(A.Sum() - v);
    }
   

}