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;
        }
        sc.close();

        System.out.println(sum);
    }
}