import java.util.*;
class Main
{
    public static void main (String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int ans = 0;
        for(int i = 0; i < n; i++){
            ans += sc.nextInt() - 1;
        }
        System.out.println(ans);
    }
}


