
import java.util.*;

public class Main {

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

    }

}
