import java.util.Scanner;

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);
        
    }
}
