static int countPaths(int[][] arr) {
        return paths(arr, 0, 0);
    }

    static int paths(int[][] grid, int row, int col) {
        int N = grid.length;
        int M = grid[0].length;

        if (row == N - 1 && col == M - 1) {
            return grid[row][col];
        }

        if (row == N - 1) {
            return grid[row][col] +  paths(grid, row, col + 1);
        } else if (col == M - 1) {
            return grid[row][col] + paths(grid, row + 1, col);
        } else {
            return grid[row][col] + Math.max(paths(grid, row + 1, col), paths(grid, row, col + 1));
        }
    }