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++) {
			ans+=sc.nextInt();
			ans--;
		}
		System.out.println(ans);
	}
}
