What's the last digit Runtime error

Hello guys,i am trying to solve this question but i get Runtime error while going through this approach.Can you please have a look at it.Thanks

Here is the link to your updated code!

hello sir,actually what code you see in my solution is taken from here
can you plz tell me whats the difference between two.And it would be best if you can explain it too.I just took the code but barely understand it :stuck_out_tongue:

sir please tell me what’s the difference between the two my code and this solution’s code.I have taken the code from very reputed programmer.Can i use his code or some fault is there.Thanks