if (fatNr > 0) { offset += (fatNr-1) * sectsPerFat * sectSize; }
offset += fatNr * fatSize;
	public static long getFatOffset(BootSector bs, int fatNr) {		long sectSize = bs.getBytesPerSector();		long sectsPerFat = bs.getSectorsPerFat();		long resSects = bs.getNrReservedSectors();				long offset = resSects * sectSize;				if (fatNr > 0) {			offset += (fatNr-1) * sectsPerFat * sectSize;		}				return offset;	}