觀察下麵一列數1,-2,-3,4,-5,6,.按如圖所示的形式,2013是第()行左邊第()個數? -1 2 -3 4 -5 6 -7 8 -9 10 -11 12 -13 14 -15 16

觀察下麵一列數1,-2,-3,4,-5,6,.按如圖所示的形式,2013是第()行左邊第()個數? -1 2 -3 4 -5 6 -7 8 -9 10 -11 12 -13 14 -15 16

45行第77個數