int pw(int a){
    if(a%2==0)return 1;else return -1;
}
float det(vector<vector<float> > &arr, int rows){
    vector<vector<float> > arr2;
    float dett=0,hk;
    if(rows==2){
       dett= (arr[0][0]*arr[1][1]-arr[0][1]*arr[1][0]);
    } else {
        for(int i=0;i<rows;i++){
           hk=arr[0][i];arr2=arr;
           arr2.erase(arr2.begin());
           for(int k=0;k<rows-1;k++)arr2[k].erase(arr2[k].begin()+i);
           dett=dett+pw(i)*hk*det(arr2,rows-1);
         }
    }
    return dett;
}

int pw(int a)
    {
        if (a % 2 == 0) return 1; else return -1;
    }
    double det(List<List<double>> arr)
    {

        int rows = arr.Count;
        List<List<double>> arr2;
        double dett = 0, hk;
        if (rows == 2)
        {
            dett = (arr.First().First() * arr.Last().Last() - arr.First().Last() * arr.Last().First());
        }
        else
        {
            for (int i = 0; i < arr.Count; i++)
            {
                hk = arr[0][i]; arr2 = arr;
                arr2.RemoveAt(0);
                foreach (List<double> k in arr2) k.RemoveAt(i);
                dett = dett + pw(i) * hk * det(arr2);
            }
        }
        return dett;
    }