Count Paths

You have a N x M matrix of cells. The cell (i, j) represents the cell at row i and column j. You can go from one cell (i, j) only down or right, that is to cells (i + 1, j) or (i, j + 1). But K cells are blocked in the matrix(you can’t visit a blocked cell). You are given coordinates of all these cells. You have to count number of ways to reach cell (N, M) if you begin at cell (1, 1). Two ways