my code is showing runtiome error on online ide,and on the compiler it is perfectly running fine.
Geerate Parantheses
You need to provide the custom input before running on the ide, you can do so by pressing the input button on the top bar, and than providing the input in below window and than press the run button.
Happy Learning 
I hope I’ve cleared your doubt. I ask you to please rate your experience here
Your feedback is very important. It helps us improve our platform and hence provide you
the learning experience you deserve.
On the off chance, you still have some questions or not find the answers satisfactory, you may reopen
the doubt.