#include<iostream>
using namespace std;
int main() {
	int n;
	int s[10000] = { 0 };
	cin >> n;
	for (int i = 0; i < n;i++) {
		cin >> s[i];
	}
	int count = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n - 1 - i; j++) {
			if (s[j] > s[j + 1]) {
				count++;
				s[j] = s[j] ^ s[j + 1];
				s[j + 1] = s[j] ^ s[j + 1];
				s[j] = s[j] ^ s[j + 1];
			}
		}
	}
	cout << count << endl;
	return 0;
}