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);
	}
}
