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++) {
            int a = sc.nextInt();
            sum += a - 1;
        }
        System.out.println(sum);
        sc.close();
    }
}