import java.util.Scanner;

public class Main{
	public static void main(String args[]) {
			Scanner scn = new Scanner(System.in);
			int n = scn.nextInt();
			long ans = 0;
			for(int i = 0;i < n;i++) {
				ans += scn.nextInt()-1;
			}
			System.out.println(ans);
			scn.close();
	}
}
