Problem Statement  
A graph is called split if the vertices can be partioned into two nonempty sets A and B such that no two distinct vertices in A are adjacent, and all pairs of distinct vertices in B are adjacent. Considering all possible ways of removing 0 or more nodes from the given graph, return how many of the resulting subgraphs are split. Two subgraphs are considered distinct if the sets of removed nodes are distinct. Character i in element j of graph is '1' if nodes i and j are adjacent, and '0' if not.  
Definition  
 
Constraints  
  graph will contain between 1 and 20 elements, inclusive.  
  Each character in graph will be '0' or '1'.  
  Each element of graph will contain exactly N characters, where N is the number of elements in graph.  
  Character i of element i of graph will always be '0'.  
  Character i of element j of graph will equal character j of element i.  
Examples  
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