code: def _ac_first_zero(X_ac):
      for i in range(1, len(X_ac)):
          if X_ac[i] <= 0:
              return i
  
      return len(X_ac)
  
imports: import math
  import numpy
  from sktime.utils.numba.njit import njit
label_desc: Use image node_id 10 for calling a global function with example usage: _ac_first_zero(X_ac) and returns: len, i