I'm killing myself over here. I'd appreciate any help offered.

I'm trying to write a program that will sum values in this series (ð/4=1-1/3+1/5-1/7+1/9-...) and print the estimate for ð. I would like for the user to choose whether to sum 100, 200, 300, 400, or 500 values to estimate ð. The more values that are added, the closer the sum *4 will be to 3.1416.

Thank you for your help.