WA in CHEFSHIP

Can anyone please explain me why my this submission gives WA .
https://www.codechef.com/viewsolution/33340493.
Problem : https://www.codechef.com/problems/CHEFSHIP
Thank You.

Your range is wrong.It should be
(l1,l1)
Check your Range Onece Again

For which of x y a b my range is wrong? I have used (l1,l1) for y …
Thanks