#include <iostream>
#include <vector>
using namespace std;

int main() {
	int n;
	cin >> n;
	
	vector<int> v(n);
	for (int i = 0; i < n; i++) {
		cin >> v[i];
	}
	
	int answer = 0;
	
	for (int sort_round = 0; sort_round < n - 1; sort_round++) {
		for (int i = 0; i <= n - 2 - sort_round; i++) {
			if (v[i] > v[i + 1]) {
				swap(v[i], v[i + 1]);
				answer += 1;
			}
		}
		
	}
	
	cout << answer;
	return 0;
}