#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int maxn = 2e5+5;
#define _time_      1.0 * clock() / CLOCKS_PER_SEC
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t;t=1;
    while(t--){
        ll n;cin>>n;
        ll a[n];
        ll ans= 0 ;
        for(int i=0;i<n;i++)cin>>a[i];
        for(int i=1;i<n;i++){
            int j = i;
            while(j>0  && a[j]<a[j-1]){
                swap(a[j] , a[j-1]);
                ans++;
                j--;
            }
        }
        cout<<ans<<"\n";
    }
}