Problem Statement  
You are given four longs K, N, A and B. Generate an integer list X of length BA+1 using the following recursive definition: X[0]=(K*A) MOD N (note that K*A may overflow a 64bit integer variable) X[i]=(X[i1]+K) MOD N Given another two longs lower and upper, return the number of elements in the list which are between lower and upper, inclusive.  
Definition  
 
Constraints  
  K will be between 0 and 10,000,000,000, inclusive.  
  N will be between 1 and 10,000,000,000, inclusive.  
  A will be between 0 and 10,000,000,000, inclusive.  
  B will be between A and 10,000,000,000, inclusive.  
  lower will be between 0 and N1, inclusive.  
  upper will be between lower and N1, inclusive.  
Examples  
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