Cells with Odd Values in a Matrix

There is an m x n matrix that is initialised to all 0's. There is also a 2D array indices where each indices[i] = [r_i, c_i] represents a 0-indexed location to perform some increment operations on the matrix.

For each location indices[i], do both of the following:

1. Increment all the cells on row r_i.
2. Increment all the cells on column c_i.

Given m, n, and indices, return the number of odd-valued cells in the matrix after applying the increment to all locations in indices.