import java.util.*;
public class Main {

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

}