If 1, negative half, one third, negative quarter and one fifth are arranged in a tower, what is the fifth number in line 100

If 1, negative half, one third, negative quarter and one fifth are arranged in a tower, what is the fifth number in line 100

According to the summation formula of arithmetic sequence, the fifth number in line 100 is the 5055th number, and because the odd number is negative, the number is 1 / 5055 of negative