import java.util.*;
 
public class Main {
	
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int N = sc.nextInt();
    	long count = 0;
    	for (int i = 0; i < N; i++) {
    		int a = sc.nextInt();
    		count += a-1;
    	}
    	System.out.println(count);
    }
}