OJ Board

I finally figured it out.
Here are some input/output cases:

INPUT

10
4 9
0 0
1 1
-1 -2
2 1
2 3
1 -1
0 -2
-1 -3
-1 -1


2 9
0 0
100 100
200 0
100 -100
20 1
34 5
50 9
55 -8
101 100

5 6
0 0
0 0
0 1
0 2
1 0
2 0

1 7
8 0
8 3
10 0
10 1
10 2
12 3
12 0

2147483647 3
2147483647 0
-2147483647 0
-234 -234 ...

Hey guys

I spent so much time on this problem,
but still can't figure out my error.
For the cases posted above, i get the same results

Please can anyone post some i/o cases?

I use graham scan for my algorithm, and output the initial length of the ribbon if it is longer than the calculated ...

Can you provide more test cases,

although I got all the posted cases right, I still get wrong answer.

Thank you for help