One day, Bobo was attending an international light exhibition and noticed a grid of lights arranged in rows and columns. Initially, all lights were off.

Bobo noticed that there were two buttons for each row and column, one for turning on and one for turning off. This means that he can perform the following four operations:

1. row on: turns on all the lights in row .
2. row off: turns off all the lights in row .
3. column on: turns on all the lights in column .
4. column off: turns off all the lights in column .

Mischievous Bobo, of course, will not miss this opportunity. You are given operations performed by Bobo. You need to determine the number of lights that are on after performing operations in sequence.

输入描述:

The first line contains three positive integers , , and  , denoting the number of rows and columns of the lights, and the number of operations that Bobo performs.

The next  lines contain an operation each, with the form of each operation already given in the problem description.

输出描述:

Output an integer in one line, denoting the number of lights that are turned on after performing  operations in order.

2 2 3
row 1 on
column 2 off
row 2 on

3

3 4 4
row 1 on
column 4 on
row 3 on
column 2 off

7

备注:

To help with understanding, we provide graphical illustrations for the second sample test case. There are three rows of lights, each with four lights. Initially, all lights are off, as shown in the figure below.



After the first operation, the state of the lights is shown in the figure below.



After the second operation, the state of the lights is shown in the figure below.



After the third operation, the state of the lights is shown in the figure below.



After the fourth operation, the state of the lights is shown in the figure below. At this point, there are still  lights on.