//Author:Pan Daoxi
#include <iostream>
using namespace std;
int main(){
    
    
	long n,t,s,a[10001];
	cin>>n;
	for(long i=1;i<=n;i++){
    
    
		cin>>a[i];
	}
	for(long j=1;j<=n-1;j++){
    
    
		for(long i=1;i<=n-j;i++){
    
    
			if(a[i]>a[i+1]){
    
    
				t=a[i];
				a[i]=a[i+1];
				a[i+1]=t; 
				s++;
			}
		}
	}
	cout<<s<<endl;
	return 0;
}