Problem Description

Maintain a $01$ matrix, where the initial matrix is all $0$.

Each operation flips one row or one column ($0$ becomes $1$, and $1$ becomes $0$).

Output how many $1$'s there are in the end.

Input Format

The first line contains $M$, the number of rows of the matrix.

The second line contains $N$, the number of columns of the matrix.

The third line contains $K$, the number of operations.

The next $K$ lines each contain one character and one number. The character R means operating on a row, and C means a column. The number indicates which row or which column.

Output Format

One line with one number, representing the final number of $1$'s.

3
3
2
R 1
C 1

4

4
5
7
R 3
C 1
C 2
R 2
R 2
C 1
R 4

10

Hint

Sample explanation:

011           01000
100           01000
100           10111
              10111

Constraints:

Translated from CCC2021 J5/S2。

Translated by ChatGPT 5