import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static int[] S(int[] A) {
        int x=A.length;
        int[]Z=new int[x*(x+1)/2];
        return Z;
    }
   static int solve(int[] A) {
        //  Return the sum of S(S(A)) modulo 10^9+7.
        int[] Y=S(S(A));
        return Y.length;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] a = new int[n];
        for(int a_i = 0; a_i < n; a_i++){
            a[a_i] = in.nextInt();
        }
        int result = solve(a);
        System.out.println(result);
        in.close();
    }
}