#include<iostream>
#include<algorithm>
#include<vector>
#include <cassert>

using namespace std;

int N, A[100];
int W[100];

int merge_and_count(int l,int r){
	if (l + 1 >= r)return 0;
	if (l + 2 == r){
		if (A[l] <= A[l + 1])return 0;
		swap(A[l], A[l + 1]);
		return 1;
	}
	int m = (l + r) / 2;
	int cl = merge_and_count(l, m);
	int cr = merge_and_count(m, r);
	int c = 0;
	int i = 1, j = m;
	int k = 1;
	while (i < m && j < r){
		if (A[i] <= A[j])W[k++] = A[i++];
		else{
			W[k++] = A[j++];
			c += floor(m-i)-1;
		}
	}
	while (i < m)W[k++] = A[i++];
	while (j < r)W[k++] = A[j++];
	assert(k == r);
	return cl + cr + c;
}

int main()
{
	cin >> N;
	for (int n = 0; n < N; n++){
		cin >> A[n];
	}
	cout << merge_and_count(0, N) << endl;
}