import java.util.*;

public class Main {

    public static void main(String[] args) {
        // write your code here
        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);
    }
}