Observe the numbers 1, - 2, - 3,4, - 5,6 in the following column. According to the form shown in the figure, 2013 is the number () on the left of line ()? -1 2 -3 4 -5 6 -7 8 -9 10 -11 12 -13 14 -15 16

Observe the numbers 1, - 2, - 3,4, - 5,6 in the following column. According to the form shown in the figure, 2013 is the number () on the left of line ()? -1 2 -3 4 -5 6 -7 8 -9 10 -11 12 -13 14 -15 16

The 77th number in line 45