using System;
using System.IO;
using System.Linq;
using System.Collections.Generic;
using System.Text;

public class Program
{

    public void Proc()
    {
        this.N = int.Parse(Reader.ReadLine());

        long[] items = new long[this.N];

        for (int i = 0; i < this.N; i++) {
            items[i] = long.Parse(Reader.ReadLine());
        }

        long ans = 0;

        for (int i = 0; i < items.Length; i++) {
            for (int j = 0; j < items.Length - 1; j++) {
                if(items[j]>items[j+1]) {
                    long tmp = items[j];
                    items[j] = items[j + 1];
                    items[j + 1] = tmp;
                    ans++;
                }
            }
        }
        Console.WriteLine(ans);
    }

    private int N;


	public class Reader
    {
        static StringReader sr;
        public static bool IsDebug = false;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (sr == null)
                {
                    sr = new StringReader(InputText.Trim());
                }
                return sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        private static string InputText = @"



5
2
5
1
4
3




";
    }

    public static void Main(string[] args)
    {
#if DEBUG
        Reader.IsDebug = true;
#endif
        Program prg = new Program();
        prg.Proc();
    }
}