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