You are given two convex polygon, and such that is strictly contained in . Output the area of the largest convex polygon that is contained in but do not have a common point with .

In the given example, the blue polygon is and the green one is . The red polygon is a valid polygon that is in but not in , however it is not the largest such polygon.

输入描述:

The first line contains an integer  ().
The following  lines contains the  points of polygon . The -th point is described by two integers  and  where .
The -th line contains an integer  ().
The following  lines contains the  points of polygon . The -th point is described by two integers  and  where .

The points of the two convex polygons will be given in counter-clockwise order.

输出描述:

Output one real number, the answer.

Your answer will be considered correct if its absolute or relative error does not exceed . Formally let your answer be , jury answer be . Your answer will be considered correct if .

4
1 1
5 1
5 5
1 5
4
3 2
4 3
3 4
2 3

4.500000000000000