import java.util.*;
public class Main {
	public static void main(String[] args){
       Scanner sc = new Scanner(System.in);
      // 取得
	  int N = sc.nextInt();
      int ans = 0;
      for(int i=0;i<N;i++){
        ans+=sc.nextInt()-1;
      }
      System.out.println(ans);
    }
}