Unique Path Grid

You are given a grid with m rows and n columns, where some cells are blocked. You can only move down or right at any point in time. Write a function that calculates the number of unique paths from the top-left corner to the bottom-right corner of the grid, while avoiding the blocked cells. Input Format: - The first line contains integers m and n (1 ≤ m, n ≤ 100). - The following m lines contain n integers, where 0 means an empty cell and 1 means a blocked cell. Output Format: - Output the number of unique paths from the top-left to the bottom-right corner of the grid. Example: Input: 3 3 0 0 0 0 1 0 0 0 0 Output: 2