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

class Program
{
    public void Solve()
    {
        int N = int.Parse(Console.ReadLine());
        int[] A = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
        int v = int.Parse(Console.ReadLine());

        int sum = 0;

        for (int i = 0; i < N; i++) { sum += A[i]; }

        Console.WriteLine(sum - v);
    }

    static void Main()
    {
        var solver = new Program();
        solver.Solve();
    }
}