#include<bits/stdc++.h>

using namespace std;

const int N = 1e4 + 1;

int n, a[N], cnt;
signed main(){
    cin >> n;
    for(int i = 1; i <= n; ++i){
        cin >> a[i];
    }
    for(int i = 1; i <= n; ++i){
        for(int j = i; j > 1 && a[j] < a[j - 1]; --j){
            swap(a[j], a[j - 1]);
            cnt++;
        }
    }
    cout << cnt;
    return 0;
}