已知向量组<img src="http://www.weimei168.com/uploads/202208/161266996681451.png" width="20" height="29" />=(1，-1，1)<img src="http://www.weimei168.com/uploads/202208/16126699713621.png" width="14" height="25" />，<img src="http://www.weimei168.com/uploads/202208/161266998654711.png" width="24" height="29" />=(-1，1，1)<img src="http://www.weimei168.com/uploads/202208/16126699713621.png" width="14" height="25" />，<img src="http://www.weimei168.com/uploads/202208/16126699921761.png" width="22" height="30" />=(1，1，-1)<img src="http://www.weimei168.com/uploads/202208/16126699713621.png" width="14" height="25" />，此向量组的秩为（）