设序列x(n)={2,3j,6,-3j,2}[-2,2]的SFT是<img src="https://static.zxtiku.com/wangke/imgs/topic/d1ae8b9d07fa7a779858cc7001342920.jpg"/>，则<img src="https://static.zxtiku.com/wangke/imgs/topic/d1ae8b9d07fa7a779858cc7001342920.jpg"/>的虚部等于。