import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        
        Scanner sc = new Scanner(System.in);
        
        int n = Integer.parseInt(sc.next());
        int ans = 0;
        for(int i = 0; i < n; i++){
            ans += Integer.parseInt(sc.next()) -1;
        }
        System.out.println(ans);
    }
}