#include <iostream>
#include <vector>
#include <fstream>

using namespace std;
ifstream fin("meh.txt");

int mergeIt(vector<int> mV, int start, int middle, int end)
{
    int count = 0;
    int b[end - start +1];
    int i = start, j = middle + 1, poz=0;

    while ((i <= middle)&&( j <= end))
    {
        if (i < j && mV[i] > 2*mV[j])
        {
            count = count + j - middle;
            b[poz] = mV[i];
            i++;
        }
        else
        {
            b[poz] = mV[j];
            j++;
        }
        poz++;
    }

    while(i <= middle)
    {
        if (j <= end && (i < j && mV[i] > 2*mV[j]))
            count = count + (j - middle);

        b[poz] = mV[i];
        poz++;
        i++;
    }

    while(j <= end)
    {
        b[poz] = mV[j];
        poz++;
        j++;
    }

    for (i = start; i <= end; i++)
        mV[i] = b[i - start];

    return count;
}

int mergeSort(vector<int> mV, int start, int end)
{
    int result1, result2, result3;

    if (start == end)
    {
        return 0;
    }
    else
    {
        int middle = (start + end) / 2;

        result1 = mergeSort(mV, start, middle);
        result2 = mergeSort(mV, middle + 1, end);
        result3 = mergeIt(mV, start, middle, end);
    }

    return result1+result2+result3;
}

int main()
{
    vector<int> myVector;
    int n, x;

    fin >> n;

    while (fin >> x)
        myVector.push_back(x);

    cout << "Nr. de inversiuni semnificative este " << mergeSort(myVector, 0, n - 1);
    return 0;
}