import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		int a [] = new int [n];

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

		int ans = 0;

        for (int i = 0; i < n; i++){
            ans = ans + a[i];
        }

		System.out.println(ans-n);


		sc.close();
	}

}
