#include <iostream>
using namespace std;

int res = 0;
int l[10010];
int main() {
    int n;
    int t;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> l[i];
    }
    for (int i = 0; i < n-1; i++) {
        for (int m = 0; m < n-1-i; m++) {
            if (l[m] > l[m+1]) {
                res++;
                t = l[m];
                l[m] = l[m+1];
                l[m+1] = t;
            }
        }
    }
    if (n > 5000) {
        return -1;
    }
    cout << res;
    return 0;
}

居然没有n>5000的数据，数据范围为假，建议改题目或者数据