human
Solve the following python programming problem given the following code:
@ classmethod 
def readUBC(TensorMesh, fileName) : 
    '
            Read UBC GIF 3DTensor mesh and generate 3D Tensor mesh in simpegTD

            Input:
            :param fileName, path to the UBC GIF mesh file

            Output:
            :param SimPEG TensorMesh object
        ' 
    def readCellLine(line) : 
        for seg in line.split () : 
            if ('*' in seg) : 
                st = seg 
                sp = seg.split ('*') 
                re = (np.array (sp [0], dtype = int) * (' ' + sp [1])) 
                line = line.replace (st, re.strip ()) 
return np.array (line.split (), dtype = float) 
msh = np.genfromtxt (fileName, delimiter = '
', dtype = np.str, comments = '!') 
    sizeM = np.array (msh [0].split (), dtype = float) 
    x0 = np.array (msh [1].split (), dtype = float) 
    h1 = readCellLine (msh [2]) 
    h2 = readCellLine (msh [3]) 
    h3temp = readCellLine (msh [4]) 
    h3 = h3temp [: : (- 1)] 
    x0 [2] = (h1 [2] - np.sum (h3)) 
    tensMsh = TensorMesh ([h1, h2, h3], x0) 
    return tensMsh 

    
    

    Fix the buggy line: x0 [2] = (h1 [2] - np.sum (h3))
assistant
#Here is Python program to fix the buggy line: x0 [2] = (h1 [2] - np.

x0 [2] = (x0 [2] - np.sum (h3))