JOI Kingdom is a mysterious kingdom which has a boundless expanse of territory. JOI-kun, the king of JOI Kingdom, is planning to cut a part of the territory and make his garden.
The territory of JOI Kingdom is considered as a sufficiently large 2-dimensional grid. The grid is paved with square cells from the top to the bottom and from the left to the right. There is a cell, which is the origin of the coordinates. Let (x,y) denote the cell one arrives at when one moves from the origin to the right direction for the distance of x cells and to the upward direction for the distance of y cells. Here, the left direction for the distance of a cells means the right direction for the distance of −a cells. Similarly, the downward direction for the distance of a cells means the upward direction for the distance of −a cells.
Some artworks are placed on the territory. The artworks are classified into two types, Type A and Type B, according to the way to be placed in the territory.
Note that a cell may contain several artworks of different kinds.
JOI-kun is planning to choose a rectangular region on the grid to make a garden. In other words, he will choose 4 integers a, b, c, d. Then the cells of the form (x,y), where x, y are integers satisfying a≤x≤b, c≤y≤d, will constitute JOI-kun’s garden. Since JOI-kun likes to see artworks of many kinds, for any of the N+M kinds of artworks, JOI-kun’s garden should contain at least one artwork of that kind. On the other hand, the citizens of JOI Kingdom will be angry if JOI-kun plans to make a too large garden. Therefore, JOI-kun wants to minimize the number of cells in the garden so that the above condition is satisfied.
Write a program which, given information of artworks, calculates the minimum number of cells in JOI-kun’s garden.
Read the following data from the standard input.
N M D
P_1 Q_1
P_2 Q_2
⋮
P_N Q_N
R_1 S_1
R_2 S_2
⋮
R_M S_M
Write one line to the standard output. The output should contain the minimum number of cells in JOI-kun’s garden.