You find yourself curiously stranded on a grid (shown in the figure below), unsure of how you got there, or how to leave. Some of the cells of the grid are blocked and cannot be (to the next row) and to the right (to the next column). You wonder, in how many different ways can you walk to the top-right corner of the grid while avoiding blocked cells? Just You find yourself curiously stranded on a grid (shown in the figure below), unsure of how you got there, or how to leave. Some of the cells of the grid are blocked and cannot be (to the next row) and to the right (to the next column). You wonder, in how many different ways can you walk to the top-right corner of the grid while avoiding blocked cells? Just