import java.util.*;

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