Euler_Problem-015.b93

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                        >v                        >00g1-10gg00g10g1-g+00g10gpv                                  
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         ^p011p00+g01g00<                         >100g10gp                  ^                  
         |!  `+2*58+g00g01                                  <
  @.g:*73<                                                                    


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We create a 21x21 grid of the edges in our graph, then we set the value on each edge to the number of possible paths to (0|0).  
For the top-left edge this is `1`. For the edges in the first row/column it is also `1`. For every other edge it is the above edge + the left edge.  
And in the end we are only interested in the value of the bottom-right edge - this value is our result.