def complement_indices(A, B):
    """Returns a complement(A-B) indices in A

       Returns the indices of A's the complementary set

       Example:
       A = ['a', 'b', 'c']
       B = ['b','c']
       result = complement_indices(A,B)
       print(result)
       # prints [0]

    """
    indices = []
    for idx, i in enumerate(A, start=0):
        if i not in B:
            indices.append(idx)
    return indices
