using System;
using System.Collections.Immutable;
using System.Linq;

namespace ABC103C
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            int[] A = Console.ReadLine().Split(' ').Select(a => int.Parse(a)).ToArray();

            int ans = 0;
            foreach (var a in A)
            {
                ans += a - 1;
            }

            Console.WriteLine(ans);
        }
    }
}