设<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/23817830_0.png">其中Ω是由<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/23817830_0_1.png">和z＝1所围成的，则I＝（　　）。{