import java.util.*;

public class Main {

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


