Problem Statement  
We have several items and a bag that can carry a maximum weight of C. The ith element of x is the weight of the ith item. Return the number of different sets of items you can carry in the bag. Two sets are considered different if there exists at least one item which is included in one set and not included in the other.  
Definition  
 
Constraints  
  x will contain between 1 and 30 elements, inclusive.  
  Each element of x will between 1 and 10^9, inclusive.  
  C will between 0 and 10^9, inclusive.  
Examples  
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