COI '15 #3 Relay
View as PDFA fleet of fishing boats set sail on the open sea from an Adriatic island. The position of each fishing boat
is described with a point in the standard coordinate system, whereas the island is described with a convex
polygon. The boats communicate via radio devices, and the island represents an obstacle for the radio
waves. More precisely, if boat  transmits a message, then boat 
 receives the message if and only if the
line segment connecting the positions of 
 and 
 does not cross the interior of the island (it is allowed to
have the line segment touch the sides and vertices of the island).
When ship  gets in trouble, it transmits the so-called Mayday message asking for help. All ships that
receive the Mayday message immediately send the so-called Relay message repeating that ship 
 needs
help. If a ship only receives the Relay message (and not the original Mayday message), then it sends
nothing.
You are given the positions of  ships denoted with integers from 
 to 
 and the location of the island.
Ship number 
 has found itself in trouble and sends the Mayday message. Determine the total number of
ships that will receive either the original Mayday message or any of the Relay messages.
Input Specification
The first line of input contains the integer  – the number of ships. The 
 of the following 
 lines
contains two integers 
 and 
 
 – the coordinates of the 
 ship. All ships are
located on different coordinates, not a single ship is located on a side or inside the polygon.
The following line contains the integer  – the number of vertices of the convex polygon describing the
island. The 
 of the following 
 lines contains two integers 
 and 
 
 – the
coordinates of the 
 vertex of the polygon. The polygon's vertices are given in the counter-clockwise
direction and form a convex polygon. No two adjacent edges will be parallel.
Output Specification
You must output the required total number of boats that will receive one of the messages.
Constraints
| Subtask | Score | Constraints | 
|---|---|---|
Sample Input 1
9
9 6
8 5
10 8
8 8
-2 3
-1 5
9 1
0 1
-1 2
7
1 1
5 1
8 3
7 5
4 6
0 5
-1 3
Sample Output 1
6
Sample Input 2
4
-1 0
-3 -20
6 10
5 10
4
3 0
3 1
0 10
0 -10
Sample Output 2
2
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