import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        int sum = 0;

        for (int i = 0; i < n; i++) {
            sum += sc.nextInt();
        }

        sc.close();

        System.out.println(sum - n);
    }
}