code: import heapq
  def 		snake_case__  (		lowercase       ,							lowercase       ,							lowercase				):
     lowerCAmelCase_:       int         =  [(0, start)]  # cost from start node,end node
     lowerCAmelCase_:       int         =  set()
     while heap:
        ((lowerCAmelCase_)     ,  (lowerCAmelCase_)):       Tuple         =  heapq.heappop(_A				)
        if u in visited:
           continue
        visited.add(_A				)
        if u == end:
           return cost
        for v, c in graph[u]:
           if v in visited:
              continue
           lowerCAmelCase_:       Dict         =  cost + c
           heapq.heappush(_A       ,							(next_item, v)				)
     return -1
  
  
  a     :			Tuple					    =						{
      'A': [['B', 2], ['C', 5]],
      'B': [['A', 2], ['D', 3], ['E', 1], ['F', 1]],
      'C': [['A', 5], ['F', 3]],
      'D': [['B', 3]],
      'E': [['B', 4], ['F', 3]],
      'F': [['C', 3], ['E', 3]],
  }
  a     :			Optional[Any]					    =						{
      'B': [['C', 1]],
      'C': [['D', 1]],
      'D': [['F', 1]],
      'E': [['B', 1], ['F', 3]],
      'F': [],
  }
  a     :			int					    =						{
      'B': [['C', 1]],
      'C': [['D', 1]],
      'D': [['F', 1]],
      'E': [['B', 1], ['G', 2]],
      'F': [],
      'G': [['F', 1]],
  }
  
  a     :			Union[str, Any]					    =						dijkstra(G, """E""", """C""")
  print(short_distance)  # E -- 3 --> F -- 3 --> C == 6
  
  a     :			Any					    =						dijkstra(Ga, """E""", """F""")
  print(short_distance)  # E -- 3 --> F == 3
  
  a     :			Union[str, Any]					    =						dijkstra(Ga, """E""", """F""")
  print(short_distance)  # E -- 2 --> G -- 1 --> F == 3
  
  if __name__ == "__main__":
   import doctest
  
   doctest.testmod()
  
  
  
  
style_context: import itertools
  def 		snake_case__  (		lowercase				):
     return (
         int("".join(combination[0:2]				)				) * int("".join(combination[2:5]				)				)
         == int("".join(combination[5:9]				)				)
     ) or (
         int("".join(combination[0]				)				) * int("".join(combination[1:5]				)				)
         == int("".join(combination[5:9]				)				)
     )
  def 		snake_case__  (		):
     return sum(
         {
             int("".join(pandigital[5:9]				)				)
             for pandigital in itertools.permutations("123456789"				)
             if is_combination_valid(lowercase				)
         }				)
  
  
  if __name__ == "__main__":
   print(solution())