#include <bits/stdc++.h>
using namespace std;
int main(){
    long long n,ans = 0;
    cin >> n;
    long long sb[n+10];
    for (long long i = 1;i <= n;i++){
        cin >> sb[i - 1];
    }
    for (long long i = 1;i < n;i++){
        for (long long j = 0;j < n - i;j++){
            if (sb[j] > sb[j + 1]){
                swap(sb[j],sb[j + 1]);
                ans++;
            }
        }
    }
    cout << ans;
}