#include <iostream>

using namespace std;

template <typename T>
void MassiveReading (T* array, int n) {
    for (int i = 0; i < n; ++i) {
        cin >> array[i];
    }
}

template <typename T>
int Sort(int n, T* array) {
    int result = 0;
    for (int i = 0; i < n - 1; i++) {
        for (int j = 0; j < n - i - 1; j++) {
            if (array[j] > array[j + 1]) {
                int temp = array[j];
                array[j] = array[j + 1];
                array[j + 1] = temp;
                result++;
            }
        }
    }
    return result;
}

int main() {
    int n;
    cin >> n;
    int* array = new int [n];
    MassiveReading(array, n);
    cout << Sort(n, array);
    delete[] array;
    return 0;
}