#include <bits/stdc++.h>

using namespace std;

int main() {
    int n, c;
    cin >> n;
    vector<int> v1;
    for (int i = 0; i < n; ++i) {
        cin >> c;
        v1.push_back(c);
    }
    int count = 0;
    //冒泡排序，计算步数
    for (int i = 0; i < n - 1; ++i) {
        for (int j = 0; j < n - 1 - i; ++j) {
            if (v1[j] > v1[j + 1]) {
                swap(v1[j], v1[j + 1]);
                count++;
            }
        }
    }
    cout << count << endl;
    return 0;
}