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

namespace yukicoderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            string[] input2 = Console.ReadLine().Split(' ');
            string input3 = Console.ReadLine();
            int trueans = 0;
            int yukians = int.Parse(input3);
            for(int i=0;i<input2.Length;i++)
            {
                trueans = trueans + int.Parse(input2[i]);
            }
            trueans = trueans - yukians;
            Console.WriteLine(trueans);
        }

    }
}