import java.util.*;


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