//
//  main.cpp
//  Counting inversions
//
//  Created by Panagiotis Hadjicostas on 17/08/2019.
//  Copyright © 2019 Panagiotis Hadjicostas. All rights reserved.
//

#include <iostream>
using namespace std;
int main() {

    int n;

    cin>>n;

    int i,j,a[n];
    int counter=0;
    for(i=0;i<n;i++){
        cin>>a[i];
        if(i>0){
            for(j=0;j<i;j++){
                if(a[i]<a[j]){
                    counter++;
                }
            }
        }
    }

    cout<<counter<<endl;

    return 0;
}