class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            string[] numList = Console.ReadLine().Split(' ');
            int yukiAns = int.Parse(Console.ReadLine());
            Console.WriteLine(AnsResult(numList)-yukiAns);
        }

        private static int AnsResult(string[] numList)
        {
            int sum = 0;
            for(int i = 0; i < numList.Length; i++)
            {
                sum += int.Parse(numList[i]);
            }
            return sum;
        }
    }