code: public int getAdIndex(int position) {
          int index = -1;
          if(position >= getOffsetValue())
              index = (position - getOffsetValue()) / (getNoOfDataBetweenAds()+1);
          //Log.d("POSITION", "index " + index + " for position " + position);
          return index;
      }
docs: Gets the ad index for this adapter position within the list of currently fetched ads.
  
  @param position the adapter position
  @return the index of the ad within the list of fetched ads