import java.util.*;

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) {
			int a = sc.nextInt();
			ans += a - 1;
		}
		sc.close();

		System.out.println(ans);
	}

}
