import java.util.Scanner;

public 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);

		sc.close();
	}
}