int bsearch(int arr[], int l, int r, int key)
{
    int mid = 0;
    while (1)
    {
        mid = (l + r) / 2;

        if (key < arr[mid])
        {
            r = mid - 1;
        }
        else if (key > arr[mid])
            {
                l = mid + 1;
            }
        else return mid;

        if (l > r)
            return -2;
    }
}
int bsearch_last(int arr[], int l, int r, int key){
    int value = -2;
    int mid = 0;

    while (l <= r){

         mid = (l + r) / 2;

        if (arr[mid] == key){
            value = mid;
            l = mid + 1;

        } else if (arr[mid] > key){
            r = mid - 1;

        } else {
            l = mid + 1;
        }
    }
    return value;
}