Firs Protection#38
On the eve of the New Year, the hares decided to strengthen the protection of the fir grove. To achieve this, they created several lines of defense. First, they surrounded the perimeter of the forest area (as a convex polygon) with a wire fence and placed the strongest hare in charge of it. Inside this enclosure, they created another fence for a slightly weaker hare, and so on. Eventually, all fir trees were protected. Now, while making the duty schedule for the hares in the forest, the chief hare comes to you for help: what is the minimum number of guards needed in one duty shift to protect all the fir trees?
The first line contains the number of trees . The second line contains numbers separated by spaces, representing the coordinates of the trees in the forest.
1 \leq N \leq 100, -1000 \leq X_i, Y_i \leq 1000.
Print a single integer — the minimum number of hares (guards) needed to protect all the fir trees.
Example 1