Advent calendar 2021
14 December
You start at the point marked A in the picture below. You want to get to the point marked B. You may travel to the right, upwards, or to the left along the black lines, but you cannot pass along the same line segment more than once.
![](javascript:showlimage("advent2021-routes.png"))
Today's number is the total number of possible routes to get from A to B.